A driving unit for use in an electric assist bicycle includes a rotation detection device in addition to a torque detection device such that the detection resolution of the rotation detection device is increased. The driving unit includes a housing, a crankshaft, a torque detection device, a rotating member, and a rotation detection device. The rotating member includes a connecting shaft and an output shaft. The connecting shaft is located at one of the ends of the rotating member disposed along its axis, and is coupled with the crankshaft in the housing. The output shaft is located at the other one of the ends of the rotating member disposed along its axis. The rotation detection device includes a detected portion and a detector. The detected portion is provided on the rotating member, and located around the central axis of the crankshaft in the housing.