To remove a malfunctioned product in the test of a semiconductor integrated circuit without increasing the number of its terminals by a method wherein a transfer-gate switch means connects a voltage generation means to an external input terminal so as to be set to continuity in the test.

A transfer-gate switch AW1 is turned on so as to be changed over to a route used in a test. When a node N1 at a voltage generation means 1 is disconnected from the noninverting terminal (+) of a differential circuit Z1 at an internal circuit 2, the gate-electrode formation part of a transistor is set forcibly to an H-level. Since the differential circuit Z1 always continues to output the H-level, a H-type transistor at an inverter 11 is always turned off, and it cannot drive the input of a latch circuit 22 to the H-level. An oscillation output signal SO is not changed to the H-level. The oscillation output signal SO remains at an L-level so as not to be changed, and an oscillation is stopped. Consequently, when the stop of the oscillation of the internal circuit 2 is confirmed in the test of an IC, it is possible to detect the disconnection between the voltage generation means 1 and the internal circuit 2.