Abstract: An optical disk drive which decreases unit costs and reduces the size of a product. The optical disk drive includes a frame, a base chassis rotatably installed on the frame, a spindle motor and a pick-up device installed on the base chassis, a tray moving into and out of the frame when a disk cartridge is mounted on the tray, a loading device for operating the tray and the base chassis, and a disk cartridge recognizing device for sensing whether or not recognition holes formed through a disk cartridge case are opened or closed to display data of the disk cartridge. The disk cartridge recognizing device includes switches fixed to a front part of the frame, and a switch operating portion for operating the switches according to whether or not the recognition holes are opened or closed.