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Contents of Significant Accounts (Tables)

12 Months Ended

Dec. 31, 2024

Contents Of Significant Accounts [Line Items]

Cash and Cash Equivalents

(1) Cash and Cash Equivalents

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Cash on hand and petty cash		$	6,200			$	6,258
Checking and savings accounts			50,322,942				25,388,395
Time deposits			80,276,114				73,507,742
Repurchase agreements collateralized by government bonds and corporate notes			1,948,359				6,097,831
Total		$	132,553,615			$	105,000,226

Summary of Fair Value of Each Investment in Equity Instrument

The fair value of each investment in equity instrument to be measured at fair value through other comprehensive income is as follows:

				As of December 31,
Type of securities		Name of securities		2023				2024
				NT$				NT$
				(In Thousands)				(In Thousands)
Common stock		UNIMICRON HOLDING LIMITED		$	2,514,120			$	2,474,388
Common stock		ITE TECH. INC.			2,100,977				2,093,997
Common stock		CHIPBOND TECHNOLOGY CORPORATION			3,843,744				3,423,750
Common stock		NOVATEK MICROELECTRONICS CORP. (NOVATEK)			8,501,851				8,255,183
Common stock		KAI-HONG ENERGY CO., LTD.			—				64,865
Common stock		SHIN-ETSU HANDOTAI TAIWAN CO., LTD.			548,205				692,265
Preferred stock		MTIC HOLDINGS PTE. LTD.			175,063				204,880

Summary of Income Recognized in Profit or Loss from Equity Instruments Designated as Fair Value Through Other Comprehensive Income

b. Dividend income recognized in profit or loss from equity instruments designated as fair value through other comprehensive income were listed below:

		For the years ended December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Held at end of period		$	1,052,336			$	888,826
Derecognized during the period			142,535				—
Total		$	1,194,871			$	888,826

Summary of Details on Derecognition of Such Investments

c. The Company reclassified its equity instrument investment in SIS as investments accounted for under the equity method. Details on derecognition of such investments are as follow:

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Fair value on the date of disposal		$	—			$	3,035,999			$	—
Cumulative gains (losses) reclassified to retained earnings due to derecognition		$	—			$	(1,628,388	)		$	—

Aging Analysis of Accounts Receivable

Aging analysis of accounts receivable:

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Neither past due		$	25,707,008			$	29,338,097
Past due:
≤ 30 days			3,008,126				3,292,457
31 to 60 days			78,668				77,929
61 to 90 days			5,599				1,249
91 to 120 days			—				1,115
≥ 121 days			517,211				23,575
Subtotal			3,609,604				3,396,325
Total		$	29,316,612			$	32,734,422

Movement of Loss Allowance

Movement of loss allowance for accounts receivable:

		For the years ended December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Beginning balance		$	209,101			$	79,062
Net recognition (reversal) for the period			(130,039	)			(68,066	)
Ending balance		$	79,062			$	10,996

Inventories, Net

(6) Inventories, Net

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Raw materials		$	10,995,569			$	10,731,866
Supplies and spare parts			6,443,172				6,238,353
Work in process			15,560,517				16,051,506
Finished goods			2,713,300				2,760,739
Total		$	35,712,558			$	35,782,464

Details of Investments Accounted for Under the Equity Method

(7) Investments Accounted for Under the Equity Method

a. Details of investments accounted for under the equity method are as follows:

		As of December 31,
		2023								2024
Investee companies		Amount				Percentage of ownership or voting rights				Amount				Percentage of ownership or voting rights
		NT$								NT$
		(In Thousands)								(In Thousands)
Listed companies
SILICON INTEGRATED SYSTEMS CORP. (SIS) (Note A)		$	2,373,060				19.02			$	1,922,753				19.02
FARADAY TECHNOLOGY CORP. (FARADAY) (Note B)			1,990,073				13.78				2,484,001				13.80
UNIMICRON TECHNOLOGY CORP. (UNIMICRON) (Note C)			13,644,560				13.05				13,824,584				13.01
Unlisted companies
MTIC HOLDINGS PTE. LTD. (Note D)			—				45.44				—				45.44
UNITECH CAPITAL INC.			625,667				42.00				556,610				42.00
TRIKNIGHT CAPITAL CORPORATION (TRIKNIGHT) (Note E)			2,109,906				40.00				1,298,112				40.00
HSUN CHIEH CAPITAL CORP.			235,098				40.00				266,066				40.00
PURIUMFIL INC.			11,474				40.00				12,340				40.00
HSUN CHIEH INVESTMENT CO., LTD. (HSUN CHIEH) (Note F)			4,126,878				36.49				4,723,930				36.49
YANN YUAN INVESTMENT CO., LTD. (YANN YUAN)			7,516,327				26.78				8,044,460				26.78
UNITED LED CORPORATION HONG KONG LIMITED			93,793				25.14				101,468				25.14
VSENSE CO., LTD. (Note D)			—				23.98				—				23.98
TRANSLINK CAPITAL PARTNERS I, L.P. (Note G)			58,964				10.38				40,545				10.38
Total		$	32,785,800							$	33,274,869

Note A: In August 2023, the board chairman of SIS changed and became the same person as the board chairman of UMC. After considering the comprehensive conditions, including ownership interest held and representation on Board of Directors of SIS, etc., the Company determines that it has significant influence over SIS and accounts for its investment in SIS as an associate. SIS was previously measured at fair value through other comprehensive income and reclassified as investments accounted for under the equity method. UMC’s share of the net fair value of SIS’s identifiable assets and liabilities was in excess of the fair value of the previously held investment in SIS at the acquisition date, and the difference was recognized as bargain purchase gain. Cumulative fair value change that was previously recognized in other comprehensive loss up to reclassification date was reclassified to retained earnings in the current period. SIS executed a capital reduction and refunded NT$499 million based on UMC’s stockholding percentage in July 2024. UMC’s stockholding percentage remains unchanged.

Note B: Beginning from June 2015, the Company accounts for its investment in FARADAY as an associate given the fact that UMC obtained the ability to exercise significant influence over FARADAY through representation on its Board of Directors. The Company participated in the capital increase of FARADAY in March 2024. Please refer to Note 7 for the relevant information.

Note C: Beginning from June 2020, the Company accounts for its investment in UNIMICRON as an associate given the fact that UMC obtained the ability to exercise significant influence over UNIMICRON through representation on its Board of Directors. On January 6, 2023, UNIMICRON issued new shares to merge with SUBTRON TECHNOLOGY CO., LTD. (SUBTRON) through share conversion. The share conversion ratio was 1 common share of SUBTRON to exchange 0.219 common shares of UNIMICRON. The 23 million shares of SUBTRON held by the Company were exchanged to 5 million common shares newly issued by UNIMICRON.

Note D: When the Company’s share of losses of an associate equals or exceeds its interest in that associate, the Company discontinues recognizing its share of further losses. Additional losses and liabilities are recognized only to the extent that the Company has incurred legal or constructive obligations or made payments on behalf of that associate.

Note E: TRIKNIGHT executed a capital reduction and refunded NT$960 million and NT$760 million based on UMC’s stockholding percentage for the years ended December 31, 2023 and 2024, respectively. UMC’s stockholding percentage remains unchanged.

Note F: HSUN CHIEH executed a capital reduction and refunded NT$343 million and NT$343 million based on UMC’s stockholding percentage for the years ended December 31, 2023 and 2024, respectively. UMC’s stockholding percentage remains unchanged.

Note G: The Company follows international accounting practices in equity accounting for limited partnerships and uses the equity method to account for these investees.

Property, Plant and Equipment

(8) Property, Plant and Equipment

a. 2023

Assets Used by the Company:

Cost:

		Land				Buildings				Machinery and equipment				Transportation equipment				Furniture and fixtures				Leasehold improvement				Construction in progress and equipment awaiting inspection				Total
		NT$				NT$				NT$				NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2023		$	1,470,216			$	37,597,769			$	953,819,688			$	64,923			$	8,061,993			$	63,075			$	55,363,943			$	1,056,441,607
Additions			—				223,177				—				—				—				—				82,213,765				82,436,942
Disposals			—				(12,160	)			(6,475,636	)			—				(112,396	)			—				(33,581	)			(6,633,773	)
Transfers and reclassifications			—				902,122				77,170,979				7,104				953,582				3,379				(54,194,544	)			24,842,622
Exchange effect			(39,878	)			(341,045	)			(3,016,210	)			(315	)			(29,711	)			(631	)			(990,932	)			(4,418,722	)
As of December 31, 2023		$	1,430,338			$	38,369,863			$	1,021,498,821			$	71,712			$	8,873,468			$	65,823			$	82,358,651			$	1,152,668,676
Accumulated Depreciation and Impairment:
		Land				Buildings				Machinery and equipment				Transportation equipment				Furniture and fixtures				Leasehold improvement				Construction in progress and equipment awaiting inspection				Total
		NT$				NT$				NT$				NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2023		$	—			$	22,731,506			$	857,737,785			$	51,597			$	6,697,517			$	59,383			$	—			$	887,277,788
Depreciation			—				1,416,727				35,031,869				4,924				490,468				4,149				—				36,948,137
Disposals			—				(12,160	)			(6,468,067	)			—				(112,330	)			—				—				(6,592,557	)
Exchange effect			—				(107,933	)			(2,212,913	)			(264	)			(19,642	)			(494	)			—				(2,341,246	)
As of December 31, 2023		$	—			$	24,028,140			$	884,088,674			$	56,257			$	7,056,013			$	63,038			$	—			$	915,292,122
Net carrying amount:
As of December 31, 2023		$	1,430,338			$	14,341,723			$	137,410,147			$	15,455			$	1,817,455			$	2,785			$	82,358,651			$	237,376,554

Assets Subject to Operating Leases:

Cost:

		Land				Buildings				Machinery and equipment				Furniture and fixtures				Total
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2023		$	545,787			$	2,443,247			$	6,345			$	1,334,291			$	4,329,670
Transfers and reclassifications			—				—				—				54,469				54,469
Exchange effect			(6,084	)			(2,330	)			—				(3,020	)			(11,434	)
As of December 31, 2023		$	539,703			$	2,440,917			$	6,345			$	1,385,740			$	4,372,705
Accumulated Depreciation and Impairment:
		Land				Buildings				Machinery and equipment				Furniture and fixtures				Total
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2023		$	—			$	1,202,812			$	6,345			$	1,302,266			$	2,511,423
Depreciation			—				94,944				—				23,395				118,339
Exchange effect			—				(688	)			—				(3,063	)			(3,751	)
As of December 31, 2023		$	—			$	1,297,068			$	6,345			$	1,322,598			$	2,626,011
Net carrying amount:
As of December 31, 2023		$	539,703			$	1,143,849			$	—			$	63,142			$	1,746,694

b. 2024

Assets Used by the Company:

Cost:

		Land				Buildings				Machinery and equipment				Transportation equipment				Furniture and fixtures				Leasehold improvement				Construction in progress and equipment awaiting inspection				Total
		NT$				NT$				NT$				NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2024		$	1,430,338			$	38,369,863			$	1,021,498,821			$	71,712			$	8,873,468			$	65,823			$	82,358,651			$	1,152,668,676
Additions			—				32,999				—				—				—				—				76,514,788				76,547,787
Disposals			—				(1,019	)			(2,198,549	)			—				(73,357	)			(43	)			(708	)			(2,273,676	)
Disposal of a subsidiary			—				(119,322	)			—				—				(40,364	)			—				—				(159,686	)
Transfers and reclassifications			—				26,772,957				93,484,809				5,087				717,154				—				(117,585,901	)			3,394,106
Exchange effect			(19,542	)			532,534				13,761,646				1,221				56,331				2,627				3,480,772				17,815,589
As of December 31, 2024		$	1,410,796			$	65,588,012			$	1,126,546,727			$	78,020			$	9,533,232			$	68,407			$	44,767,602			$	1,247,992,796
Accumulated Depreciation and Impairment:
		Land				Buildings				Machinery and equipment				Transportation equipment				Furniture and fixtures				Leasehold improvement				Construction in progress and equipment awaiting inspection				Total
		NT$				NT$				NT$				NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2024		$	—			$	24,028,140			$	884,088,674			$	56,257			$	7,056,013			$	63,038			$	—			$	915,292,122
Depreciation			—				1,474,732				42,716,755				4,663				521,994				1,879				—				44,720,023
Disposals			—				(109	)			(2,153,787	)			—				(72,920	)			(43	)			—				(2,226,859	)
Disposal of a subsidiary			—				(27,083	)			—				—				(20,056	)			—				—				(47,139	)
Exchange effect			—				199,320				12,658,149				813				49,355				2,590				—				12,910,227
As of December 31, 2024		$	—			$	25,675,000			$	937,309,791			$	61,733			$	7,534,386			$	67,464			$	—			$	970,648,374
Net carrying amount:
As of December 31, 2024		$	1,410,796			$	39,913,012			$	189,236,936			$	16,287			$	1,998,846			$	943			$	44,767,602			$	277,344,422

Assets Subject to Operating Leases:

Cost:

		Land				Buildings				Machinery and equipment				Furniture and fixtures				Total
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2024		$	539,703			$	2,440,917			$	6,345			$	1,385,740			$	4,372,705
Transfers and reclassifications			—				2,000				—				15,166				17,166
Exchange effect			(2,982	)			18,095				—				8,558				23,671
As of December 31, 2024		$	536,721			$	2,461,012			$	6,345			$	1,409,464			$	4,413,542
Accumulated Depreciation and Impairment:
		Land				Buildings				Machinery and equipment				Furniture and fixtures				Total
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2024		$	—			$	1,297,068			$	6,345			$	1,322,598			$	2,626,011
Depreciation			—				39,193				—				14,235				53,428
Exchange effect			—				10,945				—				8,543				19,488
As of December 31, 2024		$	—			$	1,347,206			$	6,345			$	1,345,376			$	2,698,927
Net carrying amount:
As of December 31, 2024		$	536,721			$	1,113,806			$	—			$	64,088			$	1,714,615

Summary of Interest Expense Capitalized

c. Details of interest expense capitalized were as follows:

		For the years ended December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Interest expense capitalized		$	9,355			$	13,560
Interest rates applied			1.48% - 1.65%				1.52% - 1.96%

Disclosure Of Detailed Information About Lease Right Of Use Assets Explanatory

a. The Company as a lessee

(a) Right-of-use Assets

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Land (including land use right)		$	5,318,986			$	5,755,484
Buildings			156,483				168,568
Machinery and equipment			1,506,824				2,082,479
Transportation equipment			16,356				12,561
Other equipment			1,706				19,923
Net		$	7,000,355			$	8,039,015

		For the years ended December 31,
		2023				2024
		NT$				NT$
Depreciation		(In Thousands)				(In Thousands)
Land (including land use right)		$	377,593			$	377,882
Buildings			93,610				87,486
Machinery and equipment			203,606				220,734
Transportation equipment			13,267				10,852
Other equipment			3,004				1,697
Total		$	691,080			$	698,651

i. For the years ended December 31, 2023 and 2024, the Company’s addition to right-of-use assets amounted to NT$206 million and NT$1,683 million, respectively.

ii. Please refer to Note 8 for right-of-use assets pledged as collateral.

(b) Lease Liabilities

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Current		$	514,324			$	636,357
Non-current			4,878,863				5,782,659
Total		$	5,393,187			$	6,419,016

Please refer to Note 6(24) for the interest expenses on the lease liabilities.

Intangible Assets

(10) Intangible Assets

2023

Cost:

		Goodwill				Software				Patents and technology license fees				Others				Total
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2023		$	15,012			$	5,669,787			$	3,422,432			$	2,953,984			$	12,061,215
Additions			—				1,399,699				346,896				999,510				2,746,105
Write-off			—				(1,498,642	)			(1,826,383	)			(632,860	)			(3,957,885	)
Reclassifications			—				(5,855	)			—				—				(5,855	)
Exchange effect			—				(98,912	)			(169,404	)			(9,993	)			(278,309	)
As of December 31, 2023		$	15,012			$	5,466,077			$	1,773,541			$	3,310,641			$	10,565,271

Accumulated Amortization and Impairment:

		Goodwill				Software				Patents and technology license fees				Others				Total
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2023		$	7,398			$	2,689,397			$	2,597,513			$	2,491,707			$	7,786,015
Amortization			—				1,741,898				277,768				535,944				2,555,610
Write-off			—				(1,498,642	)			(1,826,383	)			(632,860	)			(3,957,885	)
Exchange effect			—				(41,822	)			(139,933	)			(9,269	)			(191,024	)
As of December 31, 2023		$	7,398			$	2,890,831			$	908,965			$	2,385,522			$	6,192,716
Net carrying amount:
As of December 31, 2023		$	7,614			$	2,575,246			$	864,576			$	925,119			$	4,372,555

2024

Cost:

		Goodwill				Software				Patents and technology license fees				Others				Total
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2024		$	15,012			$	5,466,077			$	1,773,541			$	3,310,641			$	10,565,271
Additions			—				1,328,781				95,245				860,615				2,284,641
Write-off			—				(1,290,196	)			(214,874	)			(1,215,013	)			(2,720,083	)
Disposal of a subsidiary			—				(3,151	)			—				—				(3,151	)
Reclassifications			—				7,363				—				—				7,363
Exchange effect			—				(32,375	)			388,567				(4,971	)			351,221
As of December 31, 2024		$	15,012			$	5,476,499			$	2,042,479			$	2,951,272			$	10,485,262

Accumulated Amortization and Impairment:

		Goodwill				Software				Patents and technology license fees				Others				Total
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
As of January 1, 2024		$	7,398			$	2,890,831			$	908,965			$	2,385,522			$	6,192,716
Amortization			—				1,656,180				216,437				763,921				2,636,538
Write-off			—				(1,290,196	)			(214,874	)			(1,215,013	)			(2,720,083	)
Disposal of a subsidiary			—				(2,025	)			—				—				(2,025	)
Exchange effect			—				(23,675	)			252,269				(4,793	)			223,801
As of December 31, 2024		$	7,398			$	3,231,115			$	1,162,797			$	1,929,637			$	6,330,947
Net carrying amount:
As of December 31, 2024		$	7,614			$	2,245,384			$	879,682			$	1,021,635			$	4,154,315

Amortization Amounts of Intangible Assets

The amortization amounts of intangible assets were as follows:

		For the years ended December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Operating costs		$	1,144,960			$	999,321
Operating expenses		$	1,410,650			$	1,637,217

Details of Loans

(11) Short-Term Loans

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Unsecured bank loans		$	13,530,000			$	8,515,000
		As of December 31,
		2023				2024
Interest rates applied			1.69% - 2.65%				1.87% - 2.99%

Financial Liabilities at Fair Value Through Profit or Loss, Current

(12) Financial Liabilities at Fair Value through Profit or Loss, Current

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Embedded derivatives in exchangeable bonds		$	1,019,362			$	899,961
Forward exchange contracts			—				1,039
Total		$	1,019,362			$	901,000

Bonds Payable

(13) Bonds Payable

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Unsecured domestic bonds payable		$	33,100,000			$	24,600,000
Unsecured exchangeable bonds payable			5,757,373				5,757,373
Less: Discounts on bonds payable			(498,021	)			(305,805	)
Total			38,359,352				30,051,568
Less: Current or exchangeable portion due within one year			(13,779,701	)			(5,466,589	)
Net		$	24,579,651			$	24,584,979

Summary of Terms and Conditions of Bonds

a. UMC issued domestic unsecured corporate bonds. The terms and conditions of the bonds are as follows:

Term		Issuance date		Issued amount		Coupon rate				Repayment
Ten-year		In mid-June 2014		NT$3,000 million			1.95%			Interest was paid annually and the principal was fully repaid in June 2024.
Seven-year		In late March 2017		NT$2,100 million			1.43%			Interest was paid annually and the principal was fully repaid in March 2024.
Seven-year		In early October 2017		NT$3,400 million			1.13%			Interest was paid annually and the principal was fully repaid in October 2024.
Five-year		In late April 2021		NT$5,500 million			0.57%			Interest will be paid annually and the principal will be repayable in April 2026 upon maturity.
Seven-year		In late April 2021		NT$2,000 million			0.63%			Interest will be paid annually and the principal will be repayable in April 2028 upon maturity.
Ten-year (Green bond)		In late April 2021		NT$2,100 million			0.68%			Interest will be paid annually and the principal will be repayable in April 2031 upon maturity.
Five-year		In mid-December 2021		NT$5,000 million			0.63%			Interest will be paid annually and the principal will be repayable in December 2026 upon maturity.
Five-year (Green bond)		In mid-September 2023		NT$10,000 million			1.62%			Interest will be paid annually and the principal will be repayable in September 2028 upon maturity.

Defined Benefit Plan Recognized on the Consolidated Balance Sheets

iii. The defined benefit plan recognized on the consolidated balance sheets were as follows:

		As of December 31,
		2023				2024
		NT$ (In Thousands)				NT$ (In Thousands)
Present value of the defined benefit obligation		$	(4,665,498	)		$	(4,392,723	)
Fair value of plan assets			2,460,413				2,960,474
Funded status			(2,205,085	)			(1,432,249	)
Net defined benefit liabilities, noncurrent recognized on the consolidated balance sheets		$	(2,205,085	)		$	(1,432,249	)

Major Categories of Plan Assets as a Percentage of Fair Value of the Total Plan Assets

iv. The major categories of plan assets as a percentage of the fair value of the total plan assets are as follows:

		As of December 31,
		2023				2024
Cash			21	%			21	%
Equity instruments			46	%			47	%
Debt instruments			23	%			21	%
Others			10	%			11	%

Principal Underlying Actuarial Assumptions

v. The principal underlying actuarial assumptions are as follows:

		As of December 31,
		2023				2024
Discount rate			1.20	%			1.59	%
Rate of future salary increase			3.50	%			3.50	%

Expected Future Benefit Payments

vi. Expected future benefit payments are as follows:

Year		As of December 31, 2024
		NT$ (In Thousands)
2025		$	404,452
2026			367,702
2027			387,394
2028			384,106
2029			391,245
2030 and thereafter			3,010,989
Total		$	4,945,888

Sensitivity Analysis

vii. Sensitivity analysis:

		As of December 31, 2023
		Discount rate								Rate of future salary increase
		0.5% increase				0.5% decrease				0.5% increase				0.5% decrease
		NT$ (In Thousands)				NT$ (In Thousands)				NT$ (In Thousands)				NT$ (In Thousands)
Decrease (increase) in defined benefit obligation		$	137,615			$	(144,683	)		$	(117,784	)		$	113,478
		As of December 31, 2024
		Discount rate								Rate of future salary increase
		0.5% increase				0.5% decrease				0.5% increase				0.5% decrease
		NT$ (In Thousands)				NT$ (In Thousands)				NT$ (In Thousands)				NT$ (In Thousands)
Decrease (increase) in defined benefit obligation		$	154,095			$	(163,088	)		$	(137,421	)		$	131,562

Deferred Government Grants

(16) Deferred Government Grants

		As of December 31,
		2023				2024
		NT$ (In Thousands)				NT$ (In Thousands)
Beginning balance		$	4,677,444			$	2,547,022
Arising during the period			591,086				2,131,264
Recorded in profit or loss:
Other operating income			(2,663,843	)			(841,091	)
Exchange effect			(57,665	)			123,833
Ending balance		$	2,547,022			$	3,961,028
Current (classified under other current liabilities)		$	717,457			$	906,935
Non-current (classified under other noncurrent liabilities)			1,829,565				3,054,093
Total		$	2,547,022			$	3,961,028

Summary of Refund Liabilities (classified under other current liabilities)

(17) Refund Liabilities (classified under other current liabilities)

		As of December 31,
		2023				2024
		NT$ (In Thousands)				NT$ (In Thousands)
Refund liabilities		$	3,033,576			$	3,918,437

Summary of Provisions

(18) Provisions

		As of December 31,
		2023				2024
		NT$ (In Thousands)				NT$ (In Thousands)
Onerous Contracts (classified under other current liabilities)		$	57,800			$	281,244
Decommissioning Liabilities (classified under other noncurrent liabilities)			602,433				695,168
Total		$	660,233			$	976,412

Summary of Information about Provisions of Liabilities

		Onerous Contracts				Decommissioning Liabilities
		NT$ (In Thousands)				NT$ (In Thousands)
Balance as of January 1, 2024		$	57,800			$	602,433
Arising during the period			254,809				32,999
Unused provision reversed			(33,567	)			—
Discount rate adjustment and unwinding of discount from the passage of time			—				17,776
Exchange effect			2,202				41,960
Balance as of December 31, 2024		$	281,244			$	695,168

Summary of Stock Held by Associates

b. Details of UMC’s stock (thousand shares) held by the Company’s associates are as follows:

		As of December 31,
		2023				2024
HSUN CHIEH			441,371				441,371
YANN YUAN			192,963				192,963
SUBTRON, the subsidiary of UNIMICRON (Note A)			47				47
SIS (Note B)			266,580				266,580
Total			900,961				900,961

Details of Distribution

The details of appropriation were as follows:

		Appropriation of earnings (in thousand NT dollars)								Cash dividend per share (NT dollars)
		2023				2024				2023				2024
Legal reserve		$	6,255,736			$	4,738,237
Special reserve			(2,734,057	)			—
Cash dividends			37,587,102				35,787,598			$	3.00			$	2.85

Non-controlling Interests

d. Non-controlling interests:

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Balance as of January 1		$	223,181			$	343,679			$	340,859
Impact of retroactive applications			(66,089	)			—				—
Adjusted balance as of January 1			157,092				343,679				340,859
Attributable to non-controlling interests:
Net income (loss)			819,960				450,184				(104,674	)
Other comprehensive income (loss)			8				(14	)			76
Share-based payment transactions			1,490				5,817				1,913
Changes in subsidiaries’ ownership			(1,339	)			456				(7,910	)
Non-controlling interests			5,456				4,187				26,349
Derecognition of the non-controlling interests			(638,988	)			(463,450	)			—
Ending balance		$	343,679			$	340,859			$	256,613

Assumptions Used for Share-Based Payment

The compensation cost for the cash-settled share-based payment was measured at fair value initially by using Black-Scholes Option Pricing Model and will be remeasured at the end of each reporting period until settlement. As of December 31, 2024, the assumptions used are as follows:

		Granted in June 2021
Share price of measurement date (NT$/ per share)		$	43.05
Expected volatility			25.80%
Expected life			0.44 years
Expected dividend yield			6.46%
Risk-free interest rate			1.38%

Summary of Disaggregation of Revenue by Product

(21) Operating Revenues

a. Disaggregation of revenue

i. By product

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Wafer		$	265,600,173			$	211,750,622			$	221,820,412
Others			13,105,091				10,782,378				10,482,172
Total		$	278,705,264			$	222,533,000			$	232,302,584

Summary of Disaggregation of Revenue by Geography

ii. By geography

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Taiwan		$	105,213,451			$	68,360,231			$	83,758,430
China (includes Hong Kong)			39,641,613				27,545,452				37,117,309
Japan			17,053,279				11,612,866				9,107,394
Korea			25,689,385				30,872,198				26,295,063
USA			67,352,671				59,103,051				58,117,650
Europe			23,711,284				24,932,099				17,902,262
Others			43,581				107,103				4,476
Total		$	278,705,264			$	222,533,000			$	232,302,584

Summary of Disaggregation of Revenue by the Timing of Revenue Recognition

iii. By the timing of revenue recognition

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
At a point in time		$	276,175,120			$	220,283,306			$	229,505,369
Over time			2,530,144				2,249,694				2,797,215
Total		$	278,705,264			$	222,533,000			$	232,302,584

Summary of Balances of Contract Assets and Contract Liabilities

i. Contract assets, current

		As of January 1,				As of December 31,
		2023				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Sales of goods and services		$	766,691			$	1,132,477			$	1,043,680
Less: Loss allowance			(393,373	)			(392,949	)			(417,967	)
Net		$	373,318			$	739,528			$	625,713

The loss allowance was assessed by the Company primarily at an amount equal to lifetime expected credit losses. The loss allowance was mainly resulted from the suspension of the joint technology development agreement as disclosed in Note 9(7).  ii.   Contract liabilities
		As of January 1,				As of December 31,
		2023				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Sales of goods and services		$	3,985,003			$	3,681,352			$	2,660,181
Current		$	3,546,815			$	3,250,712			$	2,200,561
Non-current			438,188				430,640				459,620
Total		$	3,985,003			$	3,681,352			$	2,660,181

The movement of contract liabilities is mainly caused by the timing difference of the satisfaction of a performance of obligation and the consideration received from customers.

Employee Benefit, Depreciation and Amortization Expenses

The Company’s employee benefit, depreciation and amortization expenses are summarized as follows:

		For the years ended December 31,
		2022												2023												2024
		Operating costs				Operating expenses				Total				Operating costs				Operating expenses				Total				Operating costs				Operating expenses				Total
		NT$												NT$												NT$
		(In Thousands)												(In Thousands)												(In Thousands)
Employee benefit expenses
Salaries		$	30,074,528			$	13,928,646			$	44,003,174			$	26,693,905			$	12,002,205			$	38,696,110			$	25,959,209			$	11,485,738			$	37,444,947
Labor and health insurance			1,368,803				471,788				1,840,591				1,502,553				557,543				2,060,096				1,383,016				527,153				1,910,169
Pension			1,489,076				424,752				1,913,828				1,240,577				460,079				1,700,656				1,511,302				501,915				2,013,217
Other employee benefit expenses			373,739				165,114				538,853				421,871				196,739				618,610				401,329				207,925				609,254
Depreciation			39,305,321				1,756,609				41,061,930				36,006,021				1,545,067				37,551,088				43,740,758				1,595,934				45,336,692
Amortization			1,470,912				1,370,422				2,841,334				1,277,920				1,448,561				2,726,481				1,041,562				1,654,002				2,695,564

Details of Distribution of Employees' Compensation and Directors' Compensation

The details of distribution were as follows:

		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Employees’ compensation – Cash		$	9,160,485			$	5,439,059			$	4,509,603
Directors’ compensation			45,000				45,000				45,000

Net Other Operating Income and Expenses

(23) Net Other Operating Income and Expenses

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Government grants		$	5,058,658			$	3,862,001			$	1,337,458
Rental income from property, plant and equipment			192,833				202,082				202,010
Gain on disposal of property, plant and equipment			482,983				268,293				72,402
Others			(394,827	)			(330,050	)			(287,961	)
Total		$	5,339,647			$	4,002,326			$	1,323,909

Non-Operating Income and Expenses

(24) Non-Operating Income and Expenses

a. Other gains and losses

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Loss on valuation of financial assets and liabilities at fair value through profit or loss		$	(1,247,962	)		$	(40,553	)		$	(320,956	)
Gain (loss) on disposal of investments accounted for under the equity method			50,553				163,395				(2,093	)
Others			62,869				100,254				20,345
Total		$	(1,134,540	)		$	223,096			$	(302,704	)

b. Finance costs

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Interest expenses
Bonds payable		$	486,079			$	444,424			$	500,757
Bank loans			1,100,840				833,548				963,263
Lease liabilities			166,928				179,367				196,457
Others			31,464				16,390				18,225
Financial expenses			81,018				96,645				77,398
Total		$	1,866,329			$	1,570,374			$	1,756,100

Components of Other Comprehensive Income (Loss)

(25) Components of Other Comprehensive Income (Loss)

		For the year ended December 31, 2022
		Arising during the period				Reclassification adjustments during the period				Other comprehensive income (loss), before tax				Income tax effect				Other comprehensive income (loss), net of tax
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
Items that will not be reclassified subsequently to profit or loss:
Remeasurements of defined benefit pension plans		$	296,804			$	—			$	296,804			$	(59,361	)		$	237,443
Unrealized gains or losses from equity instruments investments measured at fair value through other comprehensive income			(4,646,064	)			—				(4,646,064	)			(71,121	)			(4,717,185	)
Share of other comprehensive income (loss) of associates and joint ventures which will not be reclassified subsequently to profit or loss			(1,694,965	)			—				(1,694,965	)			123,483				(1,571,482	)
Items that may be reclassified subsequently to profit or loss:
Exchange differences on translation of foreign operations			9,292,308				—				9,292,308				883,238				10,175,546
Share of other comprehensive income (loss) of associates and joint ventures which may be reclassified subsequently to profit or loss			91,442				—				91,442				(23,672	)			67,770
Total other comprehensive income (loss)		$	3,339,525			$	—			$	3,339,525			$	852,567			$	4,192,092

		For the year ended December 31, 2023
		Arising during the period				Reclassification adjustments during the period				Other comprehensive income (loss), before tax				Income tax effect				Other comprehensive income (loss), net of tax
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
Items that will not be reclassified subsequently to profit or loss:
Remeasurements of defined benefit pension plans		$	402,234			$	—			$	402,234			$	(80,447	)		$	321,787
Unrealized gains or losses from equity instruments investments measured at fair value through other comprehensive income			5,530,359				—				5,530,359				(243,057	)			5,287,302
Share of other comprehensive income (loss) of associates and joint ventures which will not be reclassified subsequently to profit or loss			1,610,116				—				1,610,116				(90,891	)			1,519,225
Items that may be reclassified subsequently to profit or loss:
Exchange differences on translation of foreign operations			(2,386,278	)			—				(2,386,278	)			386,660				(1,999,618	)
Share of other comprehensive income (loss) of associates and joint ventures which may be reclassified subsequently to profit or loss			(73,005	)			(1,413	)			(74,418	)			3,768				(70,650	)
Total other comprehensive income (loss)		$	5,083,426			$	(1,413	)		$	5,082,013			$	(23,967	)		$	5,058,046

		For the year ended December 31, 2024
		Arising during the period				Reclassification adjustments during the period				Other comprehensive income (loss), before tax				Income tax effect				Other comprehensive income (loss), net of tax
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
Items that will not be reclassified subsequently to profit or loss:
Remeasurements of defined benefit pension plans		$	188,451			$	—			$	188,451			$	(37,690	)		$	150,761
Unrealized gains or losses from equity instruments investments measured at fair value through other comprehensive income			(539,327	)			—				(539,327	)			25,123				(514,204	)
Share of other comprehensive income (loss) of associates and joint ventures which will not be reclassified subsequently to profit or loss			301,134				—				301,134				28,783				329,917
Items that may be reclassified subsequently to profit or loss:
Exchange differences on translation of foreign operations			8,902,745				—				8,902,745				153,317				9,056,062
Share of other comprehensive income (loss) of associates and joint ventures which may be reclassified subsequently to profit or loss			324,191				(817	)			323,374				(24,317	)			299,057
Total other comprehensive income (loss)		$	9,177,194			$	(817	)		$	9,176,377			$	145,216			$	9,321,593

Major Components of Income Tax Expense

(26) Income Tax

a. The major components of income tax expense (benefit) for the years ended December 31, 2022, 2023 and 2024 were as follows:

i. Income tax expense (benefit) recorded in profit or loss

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Current income tax expense (benefit):
Current income tax charge		$	17,582,039			$	6,426,598			$	6,105,080
Adjustments in respect of current income tax of prior periods			(585,941	)			(217,891	)			(124,430	)
Deferred income tax expense (benefit):
Deferred income tax related to origination and reversal of temporary differences			2,276,015				2,239,309				2,441,278
Deferred income tax related to recognition and derecognition of tax losses and unused tax credits			60,178				—				(34,010	)
Deferred income tax related to changes in tax rates			—				—				68
Adjustment of prior year’s deferred income tax			8,611				(120,230	)			(3,227	)
Deferred income tax arising from write-down or reversal of write-down of deferred tax assets			(14,007	)			(16,516	)			(14,565	)
Income tax expense recorded in profit or loss		$	19,326,895			$	8,311,270			$	8,370,194

ii. Deferred income tax related to components of other comprehensive income (loss)

(i) Items that will not be reclassified subsequently to profit or loss:

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Remeasurements of defined benefit pension plans		$	(59,361	)		$	(80,447	)		$	(37,690	)
Unrealized gains or losses from equity instruments investments measured at fair value through other comprehensive income			(71,121	)			(243,057	)			25,123
Share of other comprehensive income (loss) of associates and joint ventures which will not be reclassified subsequently to profit or loss			123,483				(90,891	)			28,783
Income tax related to items that will not be reclassified subsequently to profit or loss		$	(6,999	)		$	(414,395	)		$	16,216

(ii)  Items that may be reclassified subsequently to profit or loss:
		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Exchange differences on translation of foreign operations		$	883,238			$	386,660			$	153,317
Share of other comprehensive income (loss) of associates and joint ventures which may be reclassified subsequently to profit or loss			(23,672	)			3,768				(24,317	)
Income tax related to items that may be reclassified subsequently to profit or loss		$	859,566			$	390,428			$	129,000
iii.   Deferred income tax charged directly to equity
		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Adjustments of changes in net assets of associates and joint ventures accounted for using equity method		$	(2,720	)		$	(1,117	)		$	1,174

Reconciliation Between Income Tax Expense and Income Before Tax at UMC's Applicable Tax Rate

b. A reconciliation between income tax expense (benefit) and income before tax at UMC’s applicable tax rate were as follows:

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Income before tax		$	109,625,660			$	68,450,404			$	57,044,820
At UMC’s statutory income tax rate			21,925,132				13,690,081				11,408,964
Adjustments in respect of current income tax of prior periods			(585,941	)			(217,891	)			(124,430	)
Net changes in loss carry-forward and investment tax credits			(465,152	)			(2,179,234	)			(2,026,085	)
Adjustment of deferred tax assets/liabilities for write-downs/reversals and different jurisdictional tax rates			(281,319	)			211,639				559,386
Tax effect of non-taxable income and non-deductible expenses:
Tax exempt income			(4,384,566	)			(1,428,035	)			(472,756	)
Investment loss (gain)			1,827,822				(755,800	)			205,207
Dividend income			(423,027	)			(323,182	)			(231,267	)
Others			(340,745	)			(145,520	)			(610,092	)
Basic tax			—				43,506				13,414
Estimated income tax on unappropriated earnings			1,247,910				(1,160,324	)			(743,264	)
Deferred income tax related to changes in tax rates			—				—				68
Effect of different tax rates applicable to UMC and its subsidiaries			605,929				234,510				15,673
Taxes withheld in other jurisdictions			35,979				38,346				44,489
Others			164,873				303,174				330,887
Income tax expense recorded in profit or loss		$	19,326,895			$	8,311,270			$	8,370,194

Significant Components of Deferred Income Tax Assets and Liabilities

c. Significant components of deferred income tax assets and liabilities were as follows:

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Deferred income tax assets
Depreciation		$	2,396,554			$	2,616,538
Pension			436,129				281,385
Refund liabilities			306,408				318,156
Allowance for inventory valuation losses			682,909				726,023
Investment loss			314,427				328,241
Unrealized profit on intercompany sales			689,124				471,583
Others			304,860				482,577
Total deferred income tax assets			5,130,411				5,224,503
Deferred income tax liabilities
Depreciation			(2,085,916	)			(4,387,572	)
Investment gain			(2,888,534	)			(3,093,367	)
Amortizable assets			(283,405	)			(283,111	)
Others			(374,109	)			(354,201	)
Total deferred income tax liabilities			(5,631,964	)			(8,118,251	)
Net deferred income tax assets (liabilities)		$	(501,553	)		$	(2,893,748	)

Movement of Deferred Tax

d. Movement of deferred tax

		For the years ended December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Balance as of January 1		$	1,663,800			$	(501,553	)
Amounts recognized in profit or loss during the period			(2,102,563	)			(2,389,544	)
Amounts recognized in other comprehensive income (loss)			(23,967	)			145,216
Amounts recognized in equity			(1,117	)			1,174
Exchange adjustments			(37,706	)			(149,041	)
Balance as of December 31		$	(501,553	)		$	(2,893,748	)

Earnings Per Share

(27) Earnings Per Share

a. Earnings per share-basic

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Net income attributable to the parent company		$	89,478,805			$	59,688,950			$	48,779,300
Weighted-average number of ordinary shares for basic earnings per share (thousand shares)			12,095,312				12,137,954				12,173,188
Earnings per share-basic (NTD)		$	7.40			$	4.92			$	4.01

b. Earnings per share-diluted

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Net income attributable to the parent company		$	89,478,805			$	59,688,950			$	48,779,300
Weighted-average number of ordinary shares for basic earnings per share (thousand shares)			12,095,312				12,137,954				12,173,188
Effect of dilution
Restricted stocks for employees			156,098				114,974				69,881
Employees’ compensation			238,242				129,196				122,400
Weighted-average number of ordinary shares after dilution (thousand shares)			12,489,652				12,382,124				12,365,469
Earnings per share-diluted (NTD)		$	7.16			$	4.82			$	3.94

Disclosure of Equity-Settled Share-Based Payment of Restricted Stock Plans for Employees

The equity-settled share-based payment of restricted stock plans for employees in each year are as follows:

		2024 Plan		2022 Plan				2020 Plan
		1st tranche		1st tranche		2nd tranche		1st tranche		2nd tranche
Resolution date of UMC’s shareholders meeting		May 30, 2024				May 27, 2022				June 10, 2020
Maximum shares to be issued (in thousands)		66,000		50,000				233,200
Eligible employees		Qualified employees of the Company		Qualified employees of the Company				Qualified employees of UMC
Issuance of shares (in thousands)		32,956		23,060		26,728		200,030		1,268
Issuance date		December 5, 2024		December 5, 2022		December 5, 2023		September 1, 2020		June 9, 2021
Weighted-average fair value on the grant date (NT$/ per share)		$39.27		$44.40		$48.90		$21.80		$53.00

Reconciliation of Liabilities Arising from Financing Activities

(28) Reconciliation of Liabilities Arising from Financing Activities

For the year ended December 31, 2022

										Non-cash changes
Items		As of January 1, 2022				Cash Flows				Foreign exchange				Others (Note A)				As of December 31, 2022
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
Short-term loans		$	1,924,124			$	(1,965,684	)		$	41,560			$	—			$	—
Long-term loans (current portion included)			36,624,907				(18,816,259	)			1,470,694				—				19,279,342
Bonds payable (current portion included)			40,536,658				(13,305,050	)			—				953,079				28,184,687
Guarantee deposits (current portion included)			14,369,769				14,984,941				1,402,291				—				30,757,001 (Note B	)
Lease liabilities			5,068,754				(712,854	)			153,406				1,227,789 (Note C	)			5,737,095
Other financial liabilities			20,966,209				—				306,902				176,376				21,449,487

For the year ended December 31, 2023

										Non-cash changes
Items		As of January 1, 2023				Cash Flows				Foreign exchange				Others (Note A)				As of December 31, 2023
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
Short-term loans		$	—			$	13,530,000			$	—			$	—			$	13,530,000
Long-term loans (current portion included)			19,279,342				3,857,704				(253,702	)			—				22,883,344
Bonds payable (current portion included)			28,184,687				9,989,245				—				185,420				38,359,352
Guarantee deposits (current portion included)			30,757,001				10,423,345				419,040				—				41,599,386 (Note B	)
Lease liabilities			5,737,095				(666,439	)			(24,106	)			346,637				5,393,187
Other financial liabilities			21,449,487				(21,209,443	)			(330,783	)			90,739				—

For the year ended December 31, 2024

										Non-cash changes
Items		As of January 1, 2024				Cash Flows				Foreign exchange				Others (Note A)				As of December 31, 2024
		NT$				NT$				NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)				(In Thousands)
Short-term loans		$	13,530,000			$	(5,015,000	)		$	—			$	—			$	8,515,000
Long-term loans (current portion included)			22,883,344				13,178,434				415,131				—				36,476,909
Bonds payable (current portion included)			38,359,352				(8,500,465	)			—				192,681				30,051,568
Guarantee deposits (current portion included)			41,599,386				(572,321	)			1,847,429				—				42,874,494 (Note B	)
Lease liabilities			5,393,187				(731,138	)			92,617				1,664,350 (Note C	)			6,419,016

Note A: Other non-cash changes mainly consisted of discount amortization measured by the effective interest method.

Note B: Guarantee deposits mainly consisted of deposits of capacity reservation.

Note C: Mainly due to the addition to lease properties.

Restricted Stock Plan For Employees [Member]

Contents Of Significant Accounts [Line Items]

Assumptions Used for Share-Based Payment

The compensation cost for these market conditions was measured at fair value initially by using Monte Carlo Simulation on the grant date. The assumptions used are as follows:

		2024 Plan
		1st tranche
Share price of measurement date (NT$/ per share)		$	44.60
Expected volatility			23.76% - 34.32%
Expected life			2 - 4 years
Risk-free interest rate			1.40% - 1.46%

Unused tax losses [member]

Contents Of Significant Accounts [Line Items]

Unused Tax Credits and Losses

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Expiry period
1-5 years		$	15,395,514			$	19,761,573
6-10 years			22,128,180				11,407,986
Total		$	37,523,694			$	31,169,559

Plan assets [member]

Contents Of Significant Accounts [Line Items]

Defined Benefit Plan Recognized on the Consolidated Balance Sheets

ii. Movements in fair value of plan assets during the year:

		For the years ended December 31,
		2023				2024
		NT$ (In Thousands)				NT$ (In Thousands)
Beginning balance of fair value of plan assets		$	2,237,221			$	2,460,413
Items recognized as profit or loss:
Interest income on plan assets			27,742				29,525
Contribution by employer			307,556				619,281
Benefits paid			(121,305	)			(359,975	)
Remeasurements recognized in other comprehensive income (loss):
Return on plan assets, excluding amounts included in interest income			9,199				211,230
Fair value of plan assets at end of year		$	2,460,413			$	2,960,474

Present value of defined benefit obligation [member]

Contents Of Significant Accounts [Line Items]

Defined Benefit Plan Recognized on the Consolidated Balance Sheets

i. Movements in present value of defined benefit obligation during the year:

		For the years ended December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Defined benefit obligation at beginning of year		$	(5,106,623	)		$	(4,665,498	)
Items recognized as profit or loss:
Service cost			(9,893	)			(8,435	)
Interest cost			(63,322	)			(55,986	)
Subtotal			(73,215	)			(64,421	)
Remeasurements recognized in other comprehensive income (loss):
Arising from changes in demographic assumptions			—				(142,117	)
Arising from changes in financial assumptions			166,401				98,669
Experience adjustments			226,634				20,669
Subtotal			393,035				(22,779	)
Benefits paid			121,305				359,975
Defined benefit obligation at end of year		$	(4,665,498	)		$	(4,392,723	)

More than 1 year [member]

Contents Of Significant Accounts [Line Items]

Details of Loans

(14) Long-Term Loans

a. Details of long-term loans as of December 31, 2023 and 2024 were as follows:

		As of December 31,
Lenders		2023				2024				Redemption
		NT$				NT$
		(In Thousands)				(In Thousands)
Secured Long-Term Loan from Mega International Commercial Bank (1)		$	4,866			$	—			Repayable quarterly from October 24, 2019 to October 24, 2024 with monthly interest payments. Interest-only payment for the first year.
Secured Long-Term Loan from Mega International Commercial Bank (2)			13,765				9,529			Repayable quarterly from February 23, 2022 to February 22, 2027 with monthly interest payments. Interest-only payment for the first year.
Secured Long-Term Loan from Mega International Commercial Bank (3)			46,265				32,029			Repayable quarterly from December 22, 2022 to February 23, 2027 with monthly interest payments. Interest-only payment for the first year.
Secured Long-Term Loan from Mega International Commercial Bank (4)			—				41,050			Repayable monthly from April 10, 2024 to March 15, 2031 with monthly interest payments. Interest-only payment for the first three years.
Secured Long-Term Loan from Taiwan Cooperative Bank (1)			23,784				11,892			Repayable quarterly from October 19, 2015 to October 19, 2025 with monthly interest payments. Interest-only payment for the first year.
Secured Long-Term Loan from Taiwan Cooperative Bank (2)			20,000				8,000			Repayable monthly from August 13, 2020 to August 13, 2025 with monthly interest payments.
Secured Long-Term Loan from Taiwan Cooperative Bank (3)			10,345				4,138			Repayable monthly from October 29, 2020 to August 29, 2025 with monthly interest payments.
Secured Long-Term Loan from Taiwan Cooperative Bank (4)			58,916				33,667			Repayable monthly from April 15, 2021 to April 15, 2026 with monthly interest payments. Interest-only payment for the first year.
Secured Long-Term Loan from Taiwan Cooperative Bank (5)			34,400				34,400			Repayable quarterly from December 28, 2023 to December 28, 2028 with monthly interest payments. Interest-only payment for the first year.
Secured Long-Term Loan from Taiwan Cooperative Bank (6)			—				19,500			Repayable monthly from October 15, 2024 to October 15, 2031 with monthly interest payments. Interest-only payment for the first and the second year.
Secured Syndicated Loans from China Development Bank and 6 others			11,766,832				10,025,233			Repayable semi-annually from March 19, 2021 to March 18, 2031 with semi-annually interest payments. Interest-only payment for the first and the second year.
Secured Long-Term Loan from First Commercial Bank (1)			35,668				24,076			Repayable monthly from December 2, 2021 to December 2, 2026 with monthly interest payments. Interest-only payment for the first year.

		As of December 31,
Lenders		2023				2024				Redemption
		NT$				NT$
		(In Thousands)				(In Thousands)
Secured Long-Term Loan from First Commercial Bank (2)			—				63,080			Repayable monthly from March 22, 2024 to March 15, 2031 with monthly interest payments. Interest-only payment for the first three years.
Secured Long-Term Loan from KGI Bank			21,000				21,000			Settlement due on December 25, 2026 with monthly interest payments.
Secured Long-Term Loan from Shanghai Commercial Bank (1)			16,650				11,100			Repayable monthly from January 19, 2022 to December 15, 2026 with monthly interest payments. Interest-only payment for the first year.
Secured Long-Term Loan from Shanghai Commercial Bank (2)			4,980				4,046			Repayable quarterly from March 23, 2023 to March 15, 2028 with monthly interest payments. Interest-only payment for the first year.
Secured Long-Term Loan from Shanghai Commercial Bank (3)			45,000				36,563			Repayable quarterly from June 6, 2023 to March 15, 2028 with monthly interest payments. Interest-only payment for the first year.
Secured Long-Term Loan from Shanghai Commercial Bank (4)			—				9,100			Repayable quarterly from September 20, 2024 to March 15, 2028 with monthly interest payments.
Secured Long-Term Loan from CTBC Bank			131,750				131,750			Repayable semi-annually from September 25, 2023 to September 25, 2028 with monthly interest payments. Interest-only payment for the first and the second year.
Unsecured Long-Term Loan from Bank of China			1,515,790				1,237,490			Repayable semi-annually from June 24, 2023 to June 24, 2026 with quarterly interest payments.
Unsecured Long-Term Loan from Bank of Taiwan (1)			1,333,333				666,666			Repayable quarterly from March 24, 2023 to December 24, 2025 with monthly interest payments.
Unsecured Long-Term Loan from Bank of Taiwan (2)			—				2,000,000			Repayable quarterly from November 24, 2026 to November 24, 2028 with monthly interest payments.
Unsecured Long-Term Loan from Mega International Commercial Bank			—				77,250			Repayable monthly from April 10, 2024 to March 15, 2031 with monthly interest payments. Interest-only payment for the first three years.
Unsecured Long-Term Loan from Taiwan Cooperative Bank (1)			—				115,970			Repayable monthly from April 10, 2024 to March 15, 2031 with monthly interest payments. Interest-only payment for the first and the second year.

		As of December 31,
Lenders		2023				2024				Redemption
		NT$				NT$
		(In Thousands)				(In Thousands)
Unsecured Long-Term Loan from Taiwan Cooperative Bank (2)			—				3,000,000			Repayable quarterly from July 17, 2027 to July 17, 2029 with monthly interest payments.
Unsecured Long-Term Loan from Eastern International Bank			—				59,380			Repayable monthly from April 10, 2024 to March 15, 2029 with monthly interest payments. Interest-only payment for the first and the second year.
Unsecured Revolving Loan from First Commercial Bank (1) (Note A)			800,000				—			Settlement due on July 13, 2028 with monthly interest payments.
Unsecured Revolving Loan from First Commercial Bank (2) (Note B)			—				800,000			Settlement due on August 22, 2029 with monthly interest payments.
Unsecured Revolving Loan from Yuanta Commercial Bank (Note C)			3,000,000				2,000,000			Repayable annually from March 2, 2023 to March 2, 2026 with monthly interest payments.
Unsecured Revolving Loan from CTBC Bank (Note D)			4,000,000				—			Settlement due on July 20, 2025 with monthly interest payments.
Unsecured Revolving Loan from Mega International Commercial Bank (Note E)			—				3,000,000			Repayable semi-annually from November 28, 2025 to May 28, 2028 with monthly interest payments.
Unsecured Revolving Loan from Taipei Fubon Bank (Note F)			—				3,000,000			Repayable annually from January 20, 2026 to January 20, 2029 with monthly interest payments.
Unsecured Revolving Loan from DBS Bank (Note G)			—				4,700,000			Settlement due on December 25, 2029 with monthly interest payments.
Unsecured Revolving Loan from DBS Bank (Taiwan) (Note H)			—				4,000,000			Settlement due on December 13, 2029 with monthly interest payments.
Unsecured Revolving Loan from Australia and New Zealand Bank (Note I)			—				1,300,000			Settlement due on September 26, 2029 with monthly interest payments.
Subtotal			22,883,344				36,476,909
Less: Current portion			(2,227,096	)			(5,528,409	)
Total		$	20,656,248			$	30,948,500
		As of December 31,
		2023				2024
Interest rates applied			1.67% - 6.56%				1.53% - 5.49%

Note A: First Commercial Bank approved the 1-year credit loan on April 25, 2023, which offered UMC a revolving line of credit of NT$2 billion starting from the approval date to April 24, 2024. As of December 31, 2023, the unused line of credit was NT$1.2 billion.

Note B: First Commercial Bank approved the 1-year credit loan on July 9, 2024, which offered UMC a revolving line of credit of NT$2 billion starting from the approval date to July 9, 2025. As of December 31, 2024, the unused line of credit was NT$1.2 billion.

Note C: UMC entered into a 5-year loan agreement with Yuanta Commercial Bank, effective from March 3, 2021. The agreement offered UMC a revolving line of credit of NT$4 billion. This line of credit will be reduced starting from the end of the second year after the contract date and every twelve months thereafter, with a total of four adjustments. The expiration date of the agreement is March 2, 2026. As of December 31, 2023 and 2024, the unused line of credit were both nil.

Note D: UMC entered into a 5-year loan agreement with CTBC Bank, effective from December 24, 2021. The agreement offered UMC a revolving line of credit of NT$4 billion. The expiration date of the agreement is July 20, 2025. As of December 31, 2023 and 2024, the unused line of credit were nil and NT$4 billion, respectively.

Note E: UMC entered into a 5-year loan agreement with Mega International Commercial Bank, effective from November 28, 2022. The agreement offered UMC a revolving line of credit of NT$5 billion. This line of credit will be reduced starting from the end of the two years and five months after the first use and every six months thereafter, with a total of six adjustments. The expiration date of the agreement is May 28, 2028. As of December 31, 2023 and 2024, the unused line of credit were NT$5 billion and NT$2 billion, respectively.

Note F: UMC entered into a 5-year loan agreement with Taipei Fubon Bank, effective from July 20, 2023. The agreement offered UMC a revolving line of credit of NT$3 billion. This line of credit will be reduced starting from the end of the second year after the first use and every twelve months thereafter, with a total of four adjustments. The expiration date of the agreement is January 20, 2029. As of December 31, 2023 and 2024, the unused line of credit were NT$3 billion and nil, respectively.

Note G: UMC entered into a 5-year loan agreement with DBS Bank, effective from March 29, 2024. The agreement offered UMC a revolving line of credit of NT$6 billion. The expiration date of the agreement is March 29, 2029. As of December 31, 2024, the unused line of credit was NT$1.3 billion.

Note H: UMC entered into a 5-year loan agreement with DBS Bank (Taiwan), effective from October 10, 2024. The agreement offered UMC a revolving line of credit of NT$4 billion. The expiration date of the agreement is October 10, 2029. As of December 31, 2024, the unused line of credit was nil.

Note I: UMC entered into a 5-year loan agreement with Australia and New Zealand Bank, effective from September 26, 2024. The agreement offered UMC a revolving line of credit of USD 300 million. The expiration date of the agreement is September 26, 2029. As of December 31, 2024, the unused line of credit was NT$8.5 billion (USD 260 million).

Aggregated individually immaterial associates [member]

Contents Of Significant Accounts [Line Items]

Aggregate Amount of the Company's Share of its Individually Immaterial Associates

The aggregate amount of the Company’s share of all its individually immaterial associates that are accounted for using the equity method were as follows:

		For the years ended December 31,
		2022				2023				2024
		NT$				NT$				NT$
		(In Thousands)				(In Thousands)				(In Thousands)
Profit from continuing operations		$	1,626,103			$	4,307,614			$	1,238,628
Other comprehensive income (loss)			(1,706,960	)			1,540,436				570,493
Total comprehensive income (loss)		$	(80,857	)		$	5,848,050			$	1,809,121

Trade receivables [member]

Contents Of Significant Accounts [Line Items]

Financial Assets

(5) Accounts Receivable, Net

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Accounts receivable		$	29,316,612			$	32,734,422
Less: loss allowance			(79,062	)			(10,996	)
Net		$	29,237,550			$	32,723,426

Financial assets at fair value through profit or loss [member]

Contents Of Significant Accounts [Line Items]

Financial Assets

(2) Financial Assets at Fair Value through Profit or Loss

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Financial assets mandatorily measured at fair value through profit or loss
Common stocks		$	9,170,230			$	8,759,564
Preferred stocks			2,862,119				3,475,613
Funds			4,472,097				5,792,863
Convertible bonds			480,715				363,430
Forward exchange contracts			—				2
Others			153,300				65,460
Total		$	17,138,461			$	18,456,932
Current		$	443,601			$	606,018
Non-current			16,694,860				17,850,914
Total		$	17,138,461			$	18,456,932

Financial assets at fair value through other comprehensive income [member]

Contents Of Significant Accounts [Line Items]

Financial Assets

(3) Financial Assets at Fair Value through Other Comprehensive Income

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Equity instruments
Common stocks		$	17,508,897			$	17,004,448
Preferred stocks			175,063				204,880
Total		$	17,683,960			$	17,209,328
Current		$	5,753,379			$	5,893,377
Non-current			11,930,581				11,315,951
Total		$	17,683,960			$	17,209,328

Financial assets measured at amortized cost [member]

Contents Of Significant Accounts [Line Items]

Financial Assets

(4) Financial Assets Measured at Amortized Cost

		As of December 31,
		2023				2024
		NT$				NT$
		(In Thousands)				(In Thousands)
Time deposits with original maturities over three months		$	6,353,768			$	3,739,224
Current		$	6,131,077			$	3,739,224
Non-current			222,691				—
Total		$	6,353,768			$	3,739,224

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