A disk apparatus includes a supporting mechanism inwardly projecting from an inner surface of a wall of a housing, the wall having a disk insertion/ejection opening, a disk conveying mechanism that is supported by the supporting mechanism so that the disk conveying mechanism can be moved along a disk conveyance path, via which a disk is conveyed, toward a predetermined position within the housing, an engagement groove formed in the supporting mechanism and having a straight portion parallel to the disk conveyance path and a locking portion perpendicular to the straight portion, a locking member that is rotatably disposed on the disk conveying mechanism and that is engaged with the engagement groove so that the locking member is pressed toward the locking portion of the engagement groove, and an actuation mechanism for rotating the locking member to release locking of the locking member when playing back the disk.