A driving unit for use in an electric assist bicycle, comprising: a housing; a crankshaft positioned to extend through the housing; a magnetostrictive torque detection device located in the housing for detecting a torque generated in the crankshaft; a rotating member including the torque detection device, and positioned to be concentric with the crankshaft and rotatable together with the crankshaft; and a magnetic rotation detection device located in the housing for detecting rotation of the crankshaft, the rotating member including: a connecting shaft located at one of the ends of the rotating member disposed along its axis and coupled with the crankshaft within the housing; and an output shaft located at the other one of the ends of the rotating member disposed along its axis, a driving sprocket being attached to the output shaft, the rotation detection device including: a detected portion (132B, 132C) provided on the rotating member and located around a central axis of the crankshaft within the housing; and a detector (134A, 134B) configured to detect that the detected portion rotates together with the rotating member, and the detected portion (132B, 132C) being provided in a position different from that of the torque detection device as measured in an axial direction of the crankshaft, the rotational member further includes a one-way clutch in a serration engagement with the connecting shaft, the one-way clutch located closer to the driving sprocket than the torque detection device is, the one-way clutch configured to transfer to the driving sprocket a rotational force that causes the driving sprocket to rotate in a first direction around the central axis of the crankshaft and not to transfer to the driving sprocket a rotational force that causes the driving sprocket to rotate in a direction opposite the first direction, and the torque detection device is provided on the connecting shaft, characterized in that the detected portion (132B, 132C) is also provided on the connecting shaft, and the detected portion is located adjacent a side of the torque detection device opposite a side adjacent the one-way clutch as measured in an axial direction of the crankshaft, or the detected portion is located between the torque detection device and the one-way clutch as measured in an axial direction of the crankshaft. a housing; a crankshaft positioned to extend through the housing; a magnetostrictive torque detection device located in the housing for detecting a torque generated in the crankshaft; a rotating member including the torque detection device, and positioned to be concentric with the crankshaft and rotatable together with the crankshaft; and a magnetic rotation detection device located in the housing for detecting rotation of the crankshaft, the rotating member including: a connecting shaft located at one of the ends of the rotating member disposed along its axis and coupled with the crankshaft within the housing; and an output shaft located at the other one of the ends of the rotating member disposed along its axis, a driving sprocket being attached to the output shaft, a connecting shaft located at one of the ends of the rotating member disposed along its axis and coupled with the crankshaft within the housing; and an output shaft located at the other one of the ends of the rotating member disposed along its axis, a driving sprocket being attached to the output shaft, the rotation detection device including: a detected portion (132B, 132C) provided on the rotating member and located around a central axis of the crankshaft within the housing; and a detector (134A, 134B) configured to detect that the detected portion rotates together with the rotating member, and a detected portion (132B, 132C) provided on the rotating member and located around a central axis of the crankshaft within the housing; and a detector (134A, 134B) configured to detect that the detected portion rotates together with the rotating member, and the detected portion (132B, 132C) being provided in a position different from that of the torque detection device as measured in an axial direction of the crankshaft, the rotational member further includes a one-way clutch in a serration engagement with the connecting shaft, the one-way clutch located closer to the driving sprocket than the torque detection device is, the one-way clutch configured to transfer to the driving sprocket a rotational force that causes the driving sprocket to rotate in a first direction around the central axis of the crankshaft and not to transfer to the driving sprocket a rotational force that causes the driving sprocket to rotate in a direction opposite the first direction, and the torque detection device is provided on the connecting shaft, characterized in that the detected portion (132B, 132C) is also provided on the connecting shaft, and the detected portion is located adjacent a side of the torque detection device opposite a side adjacent the one-way clutch as measured in an axial direction of the crankshaft, or the detected portion is located between the torque detection device and the one-way clutch as measured in an axial direction of the crankshaft.