To easily set testing conditions such as load and vibration of a motor for testing evaluation when conducting a durability test under vibrating conditions of a motor.

A V-belt 5 is wound for connection around pulleys 3 and 4 where a motor 1 for test evaluation and a motor 2 for brake are attached to each end of its axis. Both motors 1 and 2 are driven by respective inverter power sources, and load and vibration are given to the motor 1 for test evaluation. By controlling the frequency of the inverter power source of the motor 2 for brake and controlling the velocity, test conditions of the load and vibration of the motor 1 for test evaluation can be freely set.