A disk drive that includes (i) a main chassis, (ii) a tray that is configured to have a disk removably mounted thereon and that is installed to slide into/out of the main chassis, and that includes a pickup transporting unit configured to move a pickup base back and forth in a radial direction of the disk, and (iii) a lock releasing unit that is arranged on the tray, that is driven by the pickup transporting unit, and that releases a lock of the tray from the main chassis.