TEST DEVICE

PURPOSE: To obtain the test device which is easy to see and superior in visibility and facilitates the investigation of a fault place of a tested circuit that gets out of order. CONSTITUTION: A test program for testing the operation of the tested circuit 55 and a program for actuation which actuates the test program are separated from each other, and the test program is represented by a POL. The POL 1 consists of, for example, a test value 2, a predicted value 3, a permissible value 4, a difference calculator 5, a decision unit, and a decision result 7. The tested circuit 55 has its operation tested by using the POL 1. Thus, the test program is represented by the POL, so the device is easy to see and superior in visibility, and the fault place investigation of the tested circuit 55 that gets out order is facilitated.