Abstract: A disc device which performs to ascend and descend an ascending and descending chassis mechanically by a slide plate provided at a tray at the time of insertion or discharge of the tray, and maintains the ascending and descending chassis at the ascending position or lowers it by latching or separating the above slide plate with a lock member. In order to attain the above object, a guided portion 9 is provided to the ascent and descent chassis and a guide member 82 which ascends and descends the above guided portion 9 by front and rear moving operation is positioned at both sides of the above ascending and descending chassis 2 so as to be able to move in front and rear direction. In addition, a slide plate 102 which urges the guide member 82 to a tray 100, and a lock means which latches the above slide plate 102 so as to be able to latch or separate, are provided.