<SEC-DOCUMENT>0001193125-19-025900-index.html : 20190201
<SEC-HEADER>0001193125-19-025900.hdr.sgml : 20190201
<ACCEPTANCE-DATETIME>20190201162705
ACCESSION NUMBER:		0001193125-19-025900
CONFORMED SUBMISSION TYPE:	S-8
PUBLIC DOCUMENT COUNT:		5
FILED AS OF DATE:		20190201
DATE AS OF CHANGE:		20190201
EFFECTIVENESS DATE:		20190201

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:		S-8
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-229483
		FILM NUMBER:		19560151

	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>
<DOCUMENT>
<TYPE>S-8
<SEQUENCE>1
<FILENAME>d647491ds8.htm
<DESCRIPTION>S-8
<TEXT>
Document 1 - file: d647491ds8.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-5.1
<SEQUENCE>2
<FILENAME>d647491dex51.htm
<DESCRIPTION>EX-5.1
<TEXT>
Document 2 - file: d647491dex51.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-23.2
<SEQUENCE>3
<FILENAME>d647491dex232.htm
<DESCRIPTION>EX-23.2
<TEXT>
Document 3 - file: d647491dex232.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>g647491g05x78.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: g647491g05x78.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>5
<FILENAME>g647491g76x24.gif
<DESCRIPTION>GRAPHIC
<TEXT>
Document 5 - file: g647491g76x24.gif

</DOCUMENT>
</SEC-DOCUMENT>