PURPOSE: To facilitate the operation and to lighten and miniaturize the player by placing a disk in a round recessed part of a tray.

CONSTITUTION: The disk is placed on the tray 11 fully drawn out forwardly, and when an operation switch is pressed, the tray 11 is advanced by a motor 4. Then, a semicircular columnar boss 25 is pressed by a stopper piece 14 of a lower surface of the tray 11, and hence a laterally moving member 15 is pressed by a columnar boss 26 along a groove 15b. The laterally moving member 15 is further pressed by this circular-arcuate motion, and a boss 18 on an upper surface of the laterally moving member 15 is entered into a cam groove 13 on the lower surface of the tray 11. Then, a slant part 13a is slid on the boss 18 of the laterally moving member 15 to carry out the final movement. As a result, the tray 11 is not moved forward and backward to be held in a play position by locking. Thus, since the final fixing of the tray is performed by engaging the cam groove of the tray with the laterally moving member, it is stabilized without backlash.