PURPOSE: To eliminate a selection relay by consructing the input and output of a general testing apparatus of a plurality of connectors, selecting the connectors in accordance with the content of a test and connecting a measurement cable.

CONSTITUTION: A testing connector 1a is provided at an electric motor vehicle 1, a continuity testing connector 3a, an insulation testing connector 3b and a function testing connector 3c are provided in a terminal box 3, and are respectively connected through connection cables 7aW7c and testing voltage generators 5aW5c to a computer 4. In testing, a measurement cable 2 is connected at its one end to the connector 2a of the vehicle 1, and is connected at the other end to the connectors 3aW 3d. Thus, it can eliminate the selection relay for switching a signal, thereby reducing the size of the apparatus.