It includes the impulse winding test which inspects the layer short circuit inside a coil.The function of the partial discharge test produced by bad insulation is given, and non-contact microwave antenna detects the electromagnetic waves accompanying partial discharge, in order to measure with the antenna which became independent to the testing circuit,? Even if it is included in the automatic testing machine in a factory line, measurement result cannot be easily influenced by the test environment ,and is suitable also for the direct use built into the system. This tester can simultaneously test layer short and partial discharge tests in once ,it is an innovative test equipment that can significantly reduce the testing time and equipment costs.