<SEC-DOCUMENT>0000215457-19-004934-index.html : 20190206
<SEC-HEADER>0000215457-19-004934.hdr.sgml : 20190206
<ACCEPTANCE-DATETIME>20190206150444
ACCESSION NUMBER:		0000215457-19-004934
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20190206
DATE AS OF CHANGE:		20190206

SUBJECT COMPANY:	

	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:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-58011
		FILM NUMBER:		19571201

	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

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BlackRock Inc.
		CENTRAL INDEX KEY:			0001364742
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		IRS NUMBER:				320174431
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		55 EAST 52ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10055
		BUSINESS PHONE:		212-810-5300

	MAIL ADDRESS:	
		STREET 1:		55 EAST 52ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10055

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BlackRock, Inc.
		DATE OF NAME CHANGE:	20060929

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	New BlackRock, Inc.
		DATE OF NAME CHANGE:	20060601
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>us55306n1046_020519.txt
<TEXT>
Document 1 - file: us55306n1046_020519.txt

</DOCUMENT>
</SEC-DOCUMENT>