A disk recording or reproducing apparatus includes, on a chassis ( 1 ), a pickup ( 2 ), which is moved while emitting a laser beam onto a signal surface of a disk ( 7 ), and a pair of guide shafts ( 4 ) and ( 40 ) for guiding the movement of the pickup ( 2 ). One guide shaft ( 4 ) is fitted to the pickup ( 2 ) with a fewer play than the other guide shaft ( 40 ). Both ends of the guide shaft ( 4 ) fitted to the pickup ( 2 ) with a fewer play are supported by support members ( 5 ) and ( 50 ) mounted on the chassis ( 1 ), respectively, and further, a cutout ( 52 ), into which the guide shaft ( 4 ) can be inserted, is formed on a side of at least one support member ( 50 ). A pressing member ( 9 ) including an abutting piece ( 90 ) is provided for preventing the guide shaft ( 4 ) from slipping off from the cutout ( 52 ) in the vicinity of the support member ( 50 ) having the cutout ( 52 ) formed thereat on the chassis ( 1 ). |