PURPOSE: To easily distinguish a remote controller to be connected to a test head stand controller main body of an IC tester and used for remote-controlling a test head stand even when many kinds of and a large number of remote controllers are present.

CONSTITUTION: A remote-controlling connector 2 connected to a sequencer 10 is set in a test head stand controller main body 1 of an IC tester. An electric connection cable 16 is drawn out from the remote-controlling connector 2. A connector A21 is provided at one end of the cable 16. Connectors B31 and C41 of the same kind are set in a main operation remote controller 3 and an extension remote controller 4 respectively to obtain an electric connection with the connector A21. The connectors B31 and C41 are compatible with the connector A21.