To provide a disk drive with a tray that can be smoothly taken out and in without coming-off of a gear from a rack, the tray includes, on its back surface side, a cam wall and a gear escape-preventing wall in parallel to each other along the rack with a predetermined spacing therebetween, and a guide groove provided on a rear side of the tray and connected to the gear escape-preventing wall via an inclined portion formed on the cam wall. Provided on a front side of the tray are a transverse guide groove perpendicular to a disk conveyance track, a transverse guide wall defining the transverse guide groove, a corner wall connected to the cam wall, and a corner escape-preventing wall connected to the gear escape-preventing wall. First and second bosses are provided on a rack loading, which interpose therebetween the cam wall and the gear escape-preventing wall.