A disk drive includes an outer casing having a front side formed with a tray opening, a tray disposed within the outer casing and movable with respect to the latter between retracted and extended positions and a tray cover attached to a front side of the tray. A resilient structure is interposed between the tray and the cover to provide a resilient force therebetween such that when the tray is retracted into the outer casing, the tray cover sealingly covers the tray opening in the front side of the outer casing by virtue of the resilient force provided by the resilient structure.