An optical disk apparatus includes a frame 2 which receives internal devices and can receive an optical disk 27, a tray 5 on which the optical disk 27 is rotatably mounted, a rail 4 which supports the tray so as to be moved between a mounting position where the optical disk 27 is detachably mounted and a receiving position where the optical disk 27 is received in the frame 2, a tray moving means which moves the tray 5 between the mounting position and the receiving position, a tray receiving releasing member which receives and release the tray 5 at the receiving position, and an optical disk rotation suppressing member which exerts a pressing force on the optical disk in cooperation with a tray releasing operation of the tray receiving releasing member and releases the pressing force in cooperation with a tray receiving operation of the tray receiving releasing member.