It is an object of the present invention to simplify a structure for alternatively transmitting power to a pickup moving mechanism and a disk loading mechanism by a common motor. A worm gear is attached to the rotary shaft of a motor, a worm wheel meshing this worm gear is supported on a mobile plate 8 that is movable along the rotary shaft of the motor, and first and second gears which are positioned in right and left of the worm wheel to be alternatively capable to engage with the worm wheel are arranged. The pickup moving mechanism is operated by the mesh of the first gear and the worm wheel, and the disk loading mechanism is operated by the mesh of the second gear and the worm wheel.