A disk storage medium processing apparatus includes at least an apparatus body having a disk loading/unloading slot, a traverse unit which is disposed in the apparatus body to conduct at least one of recording, deletion, and reproduction of information onto or from a disk, and a clamper supporting device for supporting a clamper which clamps the disk to the traverse unit. A disk conveying device conveys the disk into the apparatus body when a part of the disk is inserted through the disk loading/unloading slot and ejects a part of the disk through the disk loading/unloading slot from the state that the disk is housed in the apparatus body. A control device controls the disk conveying device.