PURPOSE: To improve the reliability of connection and test quality by providing two movable connection pin probes to one signal line terminal of a testing base plate and connecting them at two points.

CONSTITUTION: The device consists of the pin probes 2 and 3, signal lines 4 and 5 connected to the pin probes, a pin probe holding part 6, and an air cylinder 7 which lowers and elevates it. The testing base plate 8 is positioned on a conveyor and then the holding part 6 is lowered by the air cylinder 7 to connect the pin probes 2 and 3 to the signal terminal 1 of the testing base plate 8. An electric closed circuit is so constituted that when a voltage is applied from a signal line 4 after the connection, a current floss from the pin probe 2 to the signal line terminal 1 and then flows to the signal line 5 through the pin probe 3; and the state of the connection is confirmed. If the connection is not made, the pin probe holding part 6 is moved up and down again to connect them again, and a test is conducted when the connection is made normally.