EMERSON ELECTRIC CO — Director's Dealing 2006

Aug 16, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2006-08-14

Reporting Person: EMERSON ELECTRIC CO (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2006-08-14	Common Stock	S	45820	$19.1337	Disposed	4662137	Indirect
2006-08-15	Common Stock	S	71800	$19.932	Disposed	4590337	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1065182	Direct

Footnotes

F1: The sales were effected in multiple transactions, at varying prices, on August 14, 2006, as follows and as described in
Footnote 2 below: 12,700 shares at $19.00; 1,500 at $19.01; 1,200 at $19.02; 900 at $19.03; 500 at $19.04; 800 at $19.05;
900 at $19.06; 1,600 at $19.07; 1,300 at $19.08; 1,500 at $19.09; 1,900 at $19.10; 1,000 at $19.11; 1,200 at $19.12; 600 at
$19.13; 800 at $19.14; 1,000 at $19.15; 300 at $19.16; 600 at $19.17; 300 at $19.18; 700 at $19.19; 300 at $19.20; 400 at
$19.21; 400 at $19.22; 806 at $19.23; and 887 at $19.24.

F2: This footnote sets forth additional detail with respect to the transactions described in Footnote 1, as follows: 2,107
shares at $19.25; 800 at $19.26; 300 at $19.27; 1,200 at $19.28; 500 at $19.29; 246 at $19.30; 174 at $19.31; 200 at $19.32;
422 at $19.33; 600 at $19.34; 1,000 at $19.35; 678 at $19.36; 300 at $19.37; 200 at $19.38; 500 at $19.39; 1,100 at $19.40;
300 at $19.41; 700 at $19.42; 200 at $19.44; and 200 at $19.46. The weighted average sales price for these transactions was
$19.1337 per share.

F3: The sales were effected in multiple transactions, at varying prices, on August 15, 2006, as follows and as described in
Footnotes 4 and 5 below: 155 shares at $19.12; 45 at $19.13; 200 at $19.15; 100 at $19.16; 116 at $19.29; 600 at $19.37;
400 at $19.38; 200 at $19.39; 188 at $19.40; 200 at $19.41; 100 at $19.42; 100 at $19.43; 200 at $19.45; 100 at $19.46; 400
at $19.47; 100 at $19.48; 600 at $19.49; 300 at $19.50; 400 at $19.51; 400 at $19.52; 100 at $19.53; 600 at $19.54; 200 at
$19.55; 400 at $19.56; 200 at $19.59; and 100 at $19.62.

F4: This footnote sets forth additional detail with respect to the transactions described in Footnote 3, as follows: 200 shares
at $19.64; 200 at $19.67; 200 at $19.68; 500 at $19.69; 700 at $19.70; 100 at $19.71; 700 at $19.72; 400 at $19.73; 300 at
$19.74; 200 at $19.75; 200 at $19.76; 200 at $19.77; 800 at $19.78; 800 at $19.79; 400 at $19.80; 900 at $19.81; 300 at
$19.82; 1,000 at $19.83; 800 at $19.84; 955 at $19.85; 2,400 at $19.86; 1,300 at $19.87; 1,926 at $19.88; 2,300 at $19.89;
and 3,900 at $19.90.

F5: This footnote sets forth additional detail with respect to the transactions described in Footnotes 3 and 4, as follows:
3,850 shares at $19.91; 1,683 at $19.92; 2,117 at $19.93; 2,248 at $19.94; 4,291 at $19.95; 2,952 at $19.96; 1,909 at
$19.97; 400 at $19.98; 200 at $19.99; 677 at $20.00; 1,088 at $20.01; 700 at $20.02; 200 at $20.03; 1,000 at $20.04; 400 at
$20.05; 1,000 at $20.06; 1,000 at $20.07; 300 at $20.08; 200 at $20.09; 500 at $20.10; 400 at $20.11; 100 at $20.12; 259 at
$20.14; 2,041 at $20.15; 900 at $20.16; 1,900 at $20.17; 2,600 at $20.18; 3,300 at $20.19; 2,300 at $20.20; 200 at $20.21;
200 at $20.22; 600 at $20.23; and 2,100 at $20.24. The weighted average sales price for these transactions was $19.932 per
share.