PURPOSE: To make a disk changer compact by arranging the surface of a stocker for holding a disk and the disk-mounting surface of a tray so that the surfaces are deviated in a vertical direction.

CONSTITUTION: A stocker 4 holds a plurality of disks D at a specified interval so as to overlap in the vertical direction and can be lifted and lowered in the up and down direction. When the disk D is contained on a supporting part 4a of the stocker 4, the front side of the disk D enters a notch part 2a of a main tray 2 at a reproducing position P1. The main tray 2 at the reproducing position P1 and the stocker 4 are arranged at the closest position as far as possible so as to achieve the compact size of the device. The disk D in the stocker 4 and the disk D on a disk mounting part 2d of the main tray 2 are in the state, wherein the end parts are overlapped in three dimensions in the vertical direction.