EMERSON ELECTRIC CO — Director's Dealing 2006

Jun 21, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2006-06-19

Reporting Person: EMERSON ELECTRIC CO (10% Owner)
Reporting Person: ASTEC AMERICA INC (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2006-06-19	Common Stock	S	25000	$19.2269	Disposed	5639405	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1065182	Direct

Footnotes

F1: The sales were effected in multiple transactions, at varying prices, on June 19, 2006, as follows: 500 shares at $19.00; 800
at $19.01; 600 at $19.04; 305 at $19.09; 346 at $19.10; 454 at $19.11; 100 at $19.12; 400 at $19.13; 1,200 at $19.14; 1,200
at $19.15; 1,100 at $19.16; 800 at $19.17; 1,100 at $19.18; 700 at $19.19; 400 at $19.20; 1,800 at $19.21; 369 at $19.22;
900 at $19.23; 900 at $19.24; 800 at $19.25; 954 at $19.26; 1,020 at $19.27; 900 at $19.28; 900 at $19.29; 1,200 at $19.30;
300 at $19.31; 380 at $19.32; 600 at $19.33; 800 at $19.34; 600 at $19.35; 800 at $19.36; 100 at $19.37; 572 at $19.38; 200
at $19.39; 200 at $19.42; 200 at $19.44; 300 at $19.45; and 200 at $19.47. The weighted average sales price for these
transactions was $19.2269 per share.

F2: The reported securities are owned directly by Astec America Inc. The Reporting Person is the ultimate parent company of
Astec America Inc.

F3: The reported securities are owned directly by Emerson Electric Co.