DISK RECORDING/PLAYING DEVICE

PROBLEM TO BE SOLVED: To prevent the positional shifting of a CD during transporting by a simple structure while housing plural CDs or MDs. SOLUTION: This disk recording/playing device is provided with a large- diameter optical disk loading section 13 provided in the upper surface of a disk tray 11 to regulate the outer peripheral edge portion of a large-diameter optical disk 3, a small-diameter optical disk loading section 14 provided inside the large-diameter optical disk loading section 13 to have a loading surface lower then the same, a disk tray hole 30 provided in the peripheral edge portion of the small-diameter optical disk loading section 14, and a small-diameter optical disk position regulating member 32 positioned in the disk tray hole 30 while the disk tray 11 is loaded, and installed at a position lower than the loading surface of the large-diameter optical disk loading section 13 and higher than the upper surface of the small-diameter optical disk 4 in the state of being loaded on the small-diameter optical disk loading section 14. Thus, the floating of the small-diameter optical disk 4 from the loading surface of the small- diameter optical disk loading section 14 is prevented.