<SEC-DOCUMENT>0001193125-20-087671-index.html : 20200327
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<ACCEPTANCE-DATETIME>20200327080233
ACCESSION NUMBER:		0001193125-20-087671
CONFORMED SUBMISSION TYPE:	DEFA14A
PUBLIC DOCUMENT COUNT:		7
FILED AS OF DATE:		20200327
DATE AS OF CHANGE:		20200327
EFFECTIVENESS DATE:		20200327

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MKS INSTRUMENTS INC
		CENTRAL INDEX KEY:			0001049502
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL [3823]
		IRS NUMBER:				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:		20748080

	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: d15820ddefa14a.htm

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<DESCRIPTION>GRAPHIC
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Document 2 - file: g15820dsp005.jpg

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<FILENAME>g15820dsp006.jpg
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<TEXT>
Document 3 - file: g15820dsp006.jpg

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<SEQUENCE>4
<FILENAME>g15820dsp03a.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: g15820dsp03a.jpg

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<FILENAME>g15820dsp03b.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 5 - file: g15820dsp03b.jpg

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<SEQUENCE>6
<FILENAME>g15820dsp04a.jpg
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<TEXT>
Document 6 - file: g15820dsp04a.jpg

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<FILENAME>g15820dsp04b.jpg
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<TEXT>
Document 7 - file: g15820dsp04b.jpg

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