To prevent a shortcircuit when withstand voltage of an apparatus including a power conversion device is tested, and simplify the opening and recovering of a grounded circuit.

Contacts 8, 9 are added to a withstand voltage test switch 3 of a power conversion apparatus 2. The contact 8 is opened when a test is carried out, thereby to hinder a switch connector 5 of a power source 6 from operating. At the same time, the contact 9 is opened to free a grounded circuit of a filter capacitor 4. Aoocrdingly, the power source is prevented from being shortcircuited and the grounded circuit is opened and recovered in a simple manner.