Based on the test condition rules, the TPChecker (Test Program Checker) carefully checks for violations of the conditions of test programs that cannot be found with a run-time error check of an actual tester. The TPChecker is an optional function of the PTS-Virtualizer, which is composed of a power checker, timing checker, and settings value checker. Before the actual device is tested, the TPChecker eliminates the latch-up of a device, breakdown of a jig, reduction in margin (overkill), and defluxion of defective devices to the field, thus improving the quality of test programs.