A first shaft and a second shaft configured to connect the engine to the driving shaft and connectable/disconnectable to/from the engine, and a differential mechanism configured to connect the first shaft, the second shaft, and a rotating electrical machine to one another are provided, wherein, at the time of upshift to a gear shift stage of the second shaft from a state in which the engine is connected to the driving shaft through a gear shift stage of the first shaft, power transmission to the driving shaft through the second shaft is blocked, the second shaft is connected to the engine, power of the engine is transmitted to the second shaft by output control of the rotating electrical machine, the first shaft is disconnected from the engine, and the engine is connected to the driving shaft through the gear shift stage of the second shaft.