EMERSON ELECTRIC CO — Director's Dealing 2005

Oct 24, 2005

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2005-09-19

Reporting Person: EMERSON ELECTRIC CO (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2005-09-19	Common Stock	G	300000	—	Disposed	8663389	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1065182	Direct

Footnotes

F1: Bona fide gift to the Emerson Charitable Trust.

F2: Price is not applicable to acquisitions or dispositions resulting from bona fide gifts.

F3: The reported securities are owned directly by Astec America, Inc. The Reporting Person is the ultimate parent company of
Astec America, Inc.