EMERSON ELECTRIC CO — Director's Dealing 2006

Jun 5, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2006-06-01

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
2006-06-01	Common Stock	S	66936	$22.0615	Disposed	6250791	Indirect
2006-06-02	Common Stock	S	43355	$21.6607	Disposed	6207436	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 1, 2006, as follows and as described in Footnote
2 below: 189 shares at $21.62; 200 at $21.64; 211 at $21.65; 100 at $21.68; 500 at $21.69; 200 at $21.71; 600 at $21.73;
200 at $21.74; 546 at $21.75; 100 at $21.76; 229 at $21.77; 400 at $21.78; 600 at $21.79; 227 at $21.80; 700 at $21.81; 200
at $21.82; 900 at $21.83; 922 at $21.84; 1,100 at $21.85; 1,178 at $21.86; 2,500 at $21.87; 1,734 at $21.88; 1,511 at
$21.89; 600 at $21.90; 900 at $21.91; 1,320 at $21.92; 200 at $21.93; 500 at $21.94; 600 at $21.95; 200 at $21.96; 300 at
$21.98; 700 at $21.99; and 800 at $22.00.

F2: This footnote sets forth additional detail with respect to the transactions described in Footnote 1, as follows: 1,500
shares at $22.01; 1,100 at $22.03; 1,700 at $22.04; 3,875 at $22.05; 1,059 at $22.06; 966 at $22.07; 1,600 at $22.08; 2,600
at $22.09; 1,800 at $22.10; 1,613 at $22.11; 1,087 at $22.12; 1,300 at $22.13; 100 at $22.14; 300 at $22.16; 2,824 at
$22.17; 2,500 at $22.18; 200 at $22.19; 2,049 at $22.20; 3,182 at $22.21; 1,508 at $22.22; 400 at $22.23; 8,628 at $22.24;
900 at $22.25; 700 at $22.26; 278 at $22.27; and 2,000 at $22.28. The weighted average sales price for these transactions
was $22.0615 per share.

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

F4: The sales were effected in multiple transactions, at varying prices, on June 2, 2006, as follows and as described in Footnote
5 below: 100 shares at $21.11; 500 at $21.17; 100 at $21.19; 200 at $21.21; 300 at $21.23; 100 at $21.26; 100 at $21.27;
100 at $21.28; 100 at $21.30; 300 at $21.31; 700 at $21.33; 200 at $21.34; 300 at $21.35; 100 at $21.37; 300 at $21.40; 130
at $21.41; 470 at $21.42; 400 at $21.43; 200 at $21.44; 500 at $21.47; 100 at $21.49; 200 at $21.50; 1,600 at $21.51; 1,300
at $21.52; 1,287 at $21.53; 800 at $21.54; 900 at $21.55; 1,400 at $21.56; 1,100 at $21.57; 1,400 at $21.58; 1,400 at
$21.59; 1,700 at $21.60; 2,600 at $21.61; 2,526 at $21.62; 1,900 at $21.63; 1,000 at $21.64; 511 at $21.65; 1,400 at $21.66;
1,000 at $21.67; 500 at $21.68; 1,100 at $21.69; and 300 at $21.70.

F5: This footnote sets forth additional detail with respect to the transactions described in Footnote 4, as follows: 1,200
shares at $21.71; 700 at $21.72; 563 at $21.73; 300 at $21.74; 137 at $21.75; 600 at $21.76; 200 at $21.77; 200 at $21.78;
600 at $21.79; 400 at $21.80; 400 at $21.81; 31 at $21.82; 100 at $21.83; 200 at $21.87; 500 at $21.90; 300 at $21.95; 200
at $21.96; 800 at $21.97; 500 at $21.98; 200 at $21.99; 293 at $22.04; 100 at $22.05; 500 at $22.06; 107 at $22.08; 100 at
$22.09; 200 at $22.10; 300 at $22.15; 200 at $22.17; 300 at $22.18; 200 at $22.19; 100 at $22.21; 200 at $22.22; 200 at
$22.23; 400 at $22.24; 100 at $22.26; 200 at $22.30; 100 at $22.31; 200 at $22.32; and 200 at $22.35. The weighted average
sales price for these transactions was $21.6607 per share.

F6: The reported securities are owned directly by Emerson Electric Co.