The disk transfer device according to the present invention includes a disk tray for holding the disk during the disk transfer action and a tray driving mechanism for driving the tray forward and backward between a first position which is the retracted location of the tray corresponding to a turn table in a disk drive and a second position which is the loading and unloading location of the disk outwardly of the disk drive, wherein the disk tray comprises a main tray for supporting one side of the disk and a sub tray provided separately of the main tray for holding the other side of the disk, the main tray and the sub tray are joined to each other to have a pocket for accommodating partially the disk.