EMERSON ELECTRIC CO — Director's Dealing 2006

Jun 1, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2006-05-30

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
2006-05-30	Common Stock	S	53623	$20.9235	Disposed	6392727	Indirect
2006-05-31	Common Stock	S	75000	$21.4343	Disposed	6317727	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1065182	Direct

Footnotes

F1: The sales were effected in multiple transactions, at varying prices, on May 30, 2006, as follows and as described in Footnote
2 below: 492 shares at $20.62; 8 at $20.63; 200 at $20.64; 200 at $20.65; 100 at $20.67; 100 at $20.68; 900 at $20.69; 200
at $20.70; 600 at $20.71; 1,200 at $20.72; 1,100 at $20.73; 1,600 at $20.74; 1,700 at $20.75; 600 at $20.76; 1,064 at
$20.77; 400 at $20.78; 1,000 at $20.79; 400 at $20.80; 1,400 at $20.81; 500 at $20.82; 2,205 at $20.83; 1,457 at $20.84;
1,000 at $20.85; 400 at $20.86; 900 at $20.87; 337 at $20.88; 900 at $20.89; and 600 at $20.90.

F2: This footnote sets forth additional detail with respect to the transactions described in Footnote 1, as follows: 1,063
shares at $20.91; 400 at $20.92; 900 at $20.93; 1,100 at $20.94; 1,400 at $20.95; 1,000 at $20.96; 1,430 at $20.97; 400 at
$20.98; 2,000 at $20.99; 1,100 at $21.00; 1,800 at $21.01; 1,600 at $21.02; 2,300 at $21.03; 5,232 at $21.04; 3,498 at
$21.05; 3,337 at $21.06; 2,100 at $21.07; 700 at $21.08; and 700 at $21.09. The weighted average sales price for these
transactions was $20.9235 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 May 31, 2006, as follows and as described in Footnote
5 below: 200 shares at $21.03; 200 at $21.06; 200 at $21.07; 700 at $21.10; 100 at $21.12; 300 at $21.13; 100 at $21.14;
200 at $21.15; 500 at $21.16; 1,100 at $21.17; 500 at $21.18; 1,400 at $21.19; 726 at $21.20; 600 at $21.21; 1,126 at
$21.22; 900 at $21.23; 200 at $21.24; 400 at $21.25; 270 at $21.26; 1,100 at $21.27; 900 at $21.28; 280 at $21.29; 2,067 at
$21.30; 1,000 at $21.31; 1,200 at $21.32; 1,300 at $21.33; 2,033 at $21.34; 1,394 at $21.35; 1,606 at $21.36; 2,248 at
$21.37; 2,100 at $21.38; and 2,210 at $21.39.

F5: This footnote sets forth additional detail with respect to the transactions described in Footnote 4, as follows: 1,400
shares at $21.40; 2,200 at $21.41; 3,100 at $21.42; 1,400 at $21.43; 1,800 at $21.44; 3,200 at $21.45; 808 at $21.46; 400 at
$21.47; 1,100 at $21.48; 800 at $21.49; 1,200 at $21.50; 2,000 at $21.51; 3,200 at $21.52; 4,000 at $21.53; 1,900 at $21.54;
2,000 at $21.55; 2,500 at $21.56; 1,300 at $21.57; 1,200 at $21.58; 1,700 at $21.59; 600 at $21.60; 600 at $21.61; 200 at
$21.62; 200 at $21.63; 100 at $21.64; 700 at $21.65; 1,300 at $21.66; 1,300 at $21.67; 1,500 at $21.68; 300 at $21.69; 1,100
at $21.70; and 732 at $21.71. The weighted average sales price for these transactions was $21.4343 per share.

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