<SEC-DOCUMENT>0001193125-25-069829-index.html : 20250401
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<ACCEPTANCE-DATETIME>20250401083545
ACCESSION NUMBER:		0001193125-25-069829
CONFORMED SUBMISSION TYPE:	DEFA14A
PUBLIC DOCUMENT COUNT:		7
FILED AS OF DATE:		20250401
DATE AS OF CHANGE:		20250401

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MKS INSTRUMENTS INC
		CENTRAL INDEX KEY:			0001049502
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL [3823]
		ORGANIZATION NAME:           	08 Industrial Applications and Services
		EIN:				042277512
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		DEFA14A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-23621
		FILM NUMBER:		25796826

	BUSINESS ADDRESS:	
		STREET 1:		2 TECH DRIVE
		STREET 2:		SUITE 201
		CITY:			ANDOVER
		STATE:			MA
		ZIP:			01810
		BUSINESS PHONE:		978-645-5500

	MAIL ADDRESS:	
		STREET 1:		2 TECH DRIVE
		STREET 2:		SUITE 201
		CITY:			ANDOVER
		STATE:			MA
		ZIP:			01810
</SEC-HEADER>
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Document 1 - file: d884344ddefa14a.htm

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<DESCRIPTION>GRAPHIC
<TEXT>
Document 2 - file: g884344g03a27.jpg

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<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: g884344g03b28.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>g884344g03c29.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: g884344g03c29.jpg

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<DOCUMENT>
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<SEQUENCE>5
<FILENAME>g884344g03e31.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 5 - file: g884344g03e31.jpg

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<TYPE>GRAPHIC
<SEQUENCE>6
<FILENAME>g884344g04f32.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 6 - file: g884344g04f32.jpg

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<TYPE>GRAPHIC
<SEQUENCE>7
<FILENAME>g884344gra004.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 7 - file: g884344gra004.jpg

</DOCUMENT>
</SEC-DOCUMENT>