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Summary of Material Accounting Policies (Tables) | 12 Months Ended
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Dec. 31, 2024
Disclosure Of Summary Of Material Accounting Policies [Abstract] |
Consolidated Entities |
| b. | The consolidated entities as of December 31, 2023 and 2024 were as follows:
|  |  |  |  |  | Percentage of ownership (%) As of December 31, |
Investor |  | Subsidiary |  | Business nature |  | 2023 |  |  | 2024 |
UMC |  | UMC GROUP (USA) |  | IC Sales |  |  | 100.00 |  |  |  | 100.00 |
UMC |  | UNITED MICROELECTRONICS (EUROPE) B.V. (UME BV) |  | Marketing support activities |  |  | 100.00 |  |  |  | 100.00 |
UMC |  | UMC CAPITAL CORP. |  | Investment holding |  |  | 100.00 |  |  |  | 100.00 |
UMC |  | GREEN EARTH LIMITED (GE) |  | Investment holding |  |  | 100.00 |  |  |  | 100.00 |
UMC |  | TLC CAPITAL CO., LTD. (TLC) |  | Venture capital |  |  | 100.00 |  |  |  | 100.00 |
UMC |  | UMC INVESTMENT (SAMOA) LIMITED |  | Investment holding |  |  | 100.00 |  |  |  | 100.00 |
UMC |  | FORTUNE VENTURE CAPITAL CORP. (FORTUNE) |  | Consulting and planning for venture capital |  |  | 100.00 |  |  |  | 100.00 |
UMC |  | UMC KOREA CO., LTD. (UMC KOREA) |  | Marketing support activities |  |  | 100.00 |  |  |  | 100.00 |
UMC |  | OMNI GLOBAL LIMITED (OMNI) |  | Investment holding |  |  | 100.00 |  |  |  | 100.00 |
UMC |  | SINO PARAGON LIMITED |  | Investment holding |  |  | 100.00 |  |  |  | 100.00 |
UMC |  | BEST ELITE INTERNATIONAL LIMITED (BE) |  | Investment holding |  |  | 100.00 |  |  |  | 100.00 |
UMC |  | UNITED SEMICONDUCTOR JAPAN CO., LTD. (USJC) |  | Sales and manufacturing of integrated circuits |  |  | 100.00 |  |  |  | 100.00 |
UMC and FORTUNE |  | WAVETEK MICROELECTRONICS CORPORATION (WAVETEK) |  | Sales and manufacturing of integrated circuits |  |  | 80.00 |  |  |  | 79.54 |
TLC |  | SOARING CAPITAL CORP. |  | Investment holding |  |  | 100.00 |  |  |  | 100.00 |
SOARING CAPITAL CORP. |  | UNITRUTH ADVISOR (SHANGHAI) CO., LTD. |  | Investment holding and advisory |  |  | 100.00 |  |  |  | 100.00 |
GE |  | UNITED MICROCHIP CORPORATION |  | Investment holding |  |  | 100.00 |  |  |  | 100.00 |
FORTUNE |  | TERA ENERGY DEVELOPMENT CO., LTD. (TERA ENERGY) |  | Energy technical services |  |  | 99.01 |  |  |  | 94.93 |
TERA ENERGY |  | EVERRICH ENERGY INVESTMENT (HK) LIMITED (EVERRICH-HK) |  | Investment holding |  |  | 100.00 |  |  |  | 100.00 |
EVERRICH-HK |  | EVERRICH (JINING) NEW ENERGY TECHNOLOGY CO., LTD. (formerly EVERRICH (SHANDONG) ENERGY CO., LTD.) |  | Solar engineering integrated design services |  |  | 100.00 |  |  |  | 100.00 |
OMNI |  | UNITED MICROTECHNOLOGY CORPORATION (CALIFORNIA) |  | Research and development |  |  | 100.00 |  |  |  | 100.00 |
OMNI |  | ECP VITA PTE. LTD. |  | Insurance |  |  | 100.00 |  |  |  | 100.00 |
WAVETEK |  | WAVETEK MICROELECTRONICS CORPORATION (USA) |  | Marketing service |  |  | 100.00 |  |  |  | 100.00 |
BE |  | INFOSHINE TECHNOLOGY LIMITED (INFOSHINE) |  | Investment holding |  |  | 100.00 |  |  |  | 100.00 |
INFOSHINE |  | OAKWOOD ASSOCIATES LIMITED (OAKWOOD) |  | Investment holding |  |  | 100.00 |  |  |  | 100.00 |
OAKWOOD |  | HEJIAN TECHNOLOGY (SUZHOU) CO., LTD. (HEJIAN) |  | Sales and manufacturing of integrated circuits |  |  | 99.9985 |  |  |  | 99.9985 |
HEJIAN |  | UNITEDDS SEMICONDUCTOR (SHANDONG) CO., LTD. (UDS) (Note) |  | Integrated circuits design services |  |  | 100.00 |  |  |  | — |
UNITED MICROCHIP CORPORATION and HEJIAN |  | UNITED SEMICONDUCTOR (XIAMEN) CO., LTD. (USCXM) |  | Sales and manufacturing of integrated circuits |  |  | 100.00 |  |  |  | 100.00 |
| Note: | In August 2024, HEJIAN has disposed of its 100% of ownership interest in the subsidiary, UDS. Please refer to Note 7.

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