POWER DOOR OPENING AND CLOSING DEVICE

There is provided a power door opening device that shortens time from start of manual operation to assistance starting. The device comprises an actuator 5 that assists an operating force of a liftgate 2 supported to a vehicle body to open and close; a door-end sensor 20 that detects opening/closing motion of the liftgate 2; and a control 23 that carries out opening/closing control of the actuator on the basis that the door-end sensor 20 detects opening/closing motion of an end 2a of the liftgate 20.