A power transmitting device makes a motor in a hybrid vehicle be smaller and lighter, prevents internal resistance and inertia of the generator motor from becoming driving resistance, and can effectively utilize energy. Via a first clutch, power is transmitted from an input shaft to a transmission shaft but power transmission vice versa is blocked, and power transmission from the input shaft to the transmission shaft can be blocked. Via a second clutch, power is transmitted from the transmission shaft to the input shaft, while power transmission vice versa is blocked. Thus, when driving using only the power of the engine, power transmission from the input shaft to the transmission shaft is blocked, thereby preventing transmission of power to the generator motor. Consequently, the generator motor can be made smaller and lighter, and energy losses can be prevented.