PURPOSE: To make it possible to test an IC mounted on a device, by forcibly inputting testing data to the IC chip mounted via an IC clip.

CONSTITUTION: If the digital device becomes abnromal, an IC chip to be tested is selected and IC clip 7 is mounted on it. Next, the IC kind name is inputted from input part 1 to the test equipment and control part 2 reads the attribute of the pin of the tested IC, testing data and right-answer data from memory part 3 to set adequately clip 7 and input-output switching unit 4. Then, testing data are supplied forcibly from driver part 5 to the input part of the tested IC and at the same time, the output data of the tested IC are read out by control part 2 via receiver part 6 and compared with the right-answer data, so that when the abnormality is identified 2, the information will be displayed 8. When it is identified that the output data are mormal, on the other hand, the result is also outputted to display part 8.