<PAGE> 1
Exhibit 21
21. Subsidiaries of the registrant
WHOLLY OWNED SUBSIDIARIES
Keithley International Investment Corporation
28775 Aurora Road, Cleveland, Ohio 44139, U.S.A.
Keithley Foreign Sales Corporation
5 Norre Gade, Charlotte Amalie
St. Thomas, U.S. Virgin Islands 00801
FRANCE: Keithley Instruments SARL
3 Allee des Garays
91122 Palaiseau Cedex
GERMANY: Keithley Instruments GmbH
Landsberger Strasse 65
82110 Germering (Munich)
GREAT BRITAIN: Keithley Instruments Ltd.
The Minister, 58 Portman Road
Reading (London), Berkshire RG30 1EA
ITALY: Keithley Instruments SRL
Viale San Gimignano 38
20146 Milano
NETHERLANDS: Keithley Instruments BV
Postbus 559
4200 AN Gorinchem (Amsterdam)
SWITZERLAND: Keithley Instruments SA
Kriesbachstrasse 4
8600 Dubendorf (Zurich)
