An optical disk drive apparatus includes a tray into which an optical disk or a cartridge housing therein an optical disk may be inserted. The tray is movable first in a horizontal direction and then in a vertical direction. A cone arm having a cone disk rotatably supported at its distal end is provided and the proximal end is fixedly supported near the entrance of the apparatus where an insertion slot for inserting an optical disk or cartridge is located. The cone arm is flexible and elongated in shape and has its intermediate portion operatively coupled to a bracket fixedly mounted on the tray, so that as the tray moves horizontally and then vertically, the cone arm is automatically deflected to bring the cone disk in engagement with the optical disk, thereby causing the optical disk properly mounted on a spindle motor. Further, an oil damper is interconnected with both a loading/ejecting arm and a shutter opening and closing member.