A medicine feeder's drive unit includes a drive motor, a gear transmission device, an output shaft and a switcher. The gear transmission device is constituted by a normal-rotation transmission path and a reverse-rotation transmission path provided between a motor shaft of the drive motor and the output shaft. The switcher selects one of the transmission paths for output of driving power from the drive motor. Thus, a jammed tablet in the medicine feeder can be cleared upon detection thereof, and reverse rotation of a rotor can be achieved without driving the motor in a reverse rotating direction, i.e., while the motor is in normal rotation setting.