To avoid a loss due to the forced co-rotation of an electric machine during a drive using an internal combustion engine by selectively spearing and connecting the electric machine from and to a remaining power train by the second clutch integrated with the electric machine.

An internal combustion engine 10 is connected to a transmission 14 and a differential gear 16 via a separation clutch 12. The engine 10 is connected to a driving wheel 18 or 20. Also, a clutch 24 is integrated with a motor- driven unit 22, and the rotor of the motor-driven unit 22 is connected to and separated from an added transmission input shaft by the clutch 24. In addition, as the transmission 14 is laid between the clutch 24 of the motor-driven unit 22 and the separation clutch 12, drive of the internal combustion engine 10 can be performed without the co-rotation of the rotor of the motor-driven unit 22. According to this construction, the core loss of an electric motor can be avoided.