A disk apparatus includes a chassis outer sheath with a base body and a lid. A slider mechanism is disposed on one end of a traverse, the slider mechanism includes a vertically moving cam mechanism which brings the traverse close to and away from the base body. A cam groove of the vertically moving cam mechanism has a first cam portion which moves together with the slider mechanism and a second cam portion which is displaced with respect to the first cam portion. When a vertically moving pin of the vertically moving cam mechanism exceeds a predetermined height in the cam groove, the second cam portion rises and the second cam portion limits movement of the vertically moving pin. When the vertically moving pin is equal to or lower than the predetermined height in the cam groove, the second cam portion is held at its lowered position.