To prolong a life without overloading an intensifying valve by receiving an intensifying request pulse from an intensifying pulse generation means and switching primary pneumatics and secondary pneumatics.

An intensifying request signal from a switch 20i generating the intensifying request signal is sent to the OR means 22 of a semiconductor test device main body 1-side by a connection cable 21i. The OR means 22 detects all the intensifying request signals of the switches 20i. The detected intensifying request signal is sent to the intensifying pulse generation means 23. The intensifying pulse generation means 23 generates solenoid valve driving pulse and sends it to an air switch means 24. The air switch means 24 changes over use compression air 15 front primary compression air 11 to secondary compression air 14 while the solenoid valve driving pulse exists. When the solenoid valve driving pulse is eliminated, use compression air 15 returns again from secondary compression air 14 to primary compression air 11. At that time, use compression air 15 supplies necessary secondary pneumatics P2 at the time of attaching/ detaching TH and DI parts and connecting a handler and gives primary pneumatics P1 in other cases.