EMERSON ELECTRIC CO — Director's Dealing 2006

Sep 8, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2006-09-06

Reporting Person: EMERSON ELECTRIC CO (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2006-09-06	Common Stock	S	30106	$20.2796	Disposed	3849941	Indirect
2006-09-07	Common Stock	S	28692	$20.2869	Disposed	3821249	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1065182	Direct

Footnotes

F1: The sales were effected in multiple transactions, at varying prices, on September 6, 2006, as follows and as described in
Footnote 2 below: 100 shares at $20.14; 581 at $20.16; 2,300 at $20.17; 1,800 at $20.18; 1,400 at $20.19; 1,000 at $20.20;
2,100 at $20.21; 1,700 at $20.22; 2,025 at $20.23; 1,800 at $20.24; 1,200 at $20.25; 500 at $20.26; 1,300 at $20.27; 1,863
at $20.28; 337 at $20.29; 800 at $20.30; 400 at $20.31; 600 at $20.32; 500 at $20.33; 400 at $20.34; and 100 at $20.35.

F2: This footnote sets forth additional detail with respect to the transactions described in Footnote 1, as follows: 1,200
shares at $20.36; 400 at $20.37; 400 at $20.38; 300 at $20.39; 930 at $20.40; 1,000 at $20.41; 300 at $20.42; 370 at $20.43;
200 at $20.44; 100 at $20.45; 300 at $20.46; 500 at $20.47; 300 at $20.48; 100 at $20.50; 200 at $20.51; 100 at $20.53; 100
at $20.56; 200 at $20.57; 200 at $20.58; and 100 at $20.68. The weighted average sales price for these transactions was
$20.2796 per share.

F3: The sales were effected in multiple transactions, at varying prices, on September 7, 2006, as follows and as described in
Footnote 4 below: 300 shares at $19.83; 200 at $19.84; 200 at $19.85; 200 at $19.87; 100 at $19.88; 200 at $19.89; 200 at
$19.90; 100 at $19.91; 300 at $19.92; 200 at $19.93; 263 at $19.95; 600 at $19.96; 200 at $19.97; 200 at $19.98; 400 at
$20.00; 600 at $20.01; 200 at $20.02; 100 at $20.03; 100 at $20.04; 100 at $20.06; 100 at $20.07; 200 at $20.09; 300 at
$20.10; and 200 at $20.13.

F4: This footnote sets forth additional detail with respect to the transactions described in Footnote 3, as follows: 100 shares
at $20.14; 163 at $20.16; 100 at $20.17; 200 at $20.18; 200 at $20.22; 100 at $20.24; 300 at $20.25; 100 at $20.27; 400 at
$20.28; 700 at $20.29; 1,000 at $20.30; 1,100 at $20.31; 2,076 at $20.32; 4,424 at $20.33; 900 at $20.34; 2,500 at $20.35;
1,000 at $20.36; 1,100 at $20.38; 300 at $20.39; 700 at $20.41; 600 at $20.42; 1,200 at $20.43; 300 at $20.44; 800 at
$20.45; 300 at $20.46; 500 at $20.47; 500 at $20.53; 300 at $20.54; 600 at $20.55; 300 at $20.56; and 266 at $20.57. The
weighted average sales price for these transactions was $20.2869 per share.