A disk recording and playback apparatus comprises a housing base, a cam body rotatably mounted on the housing base and actuatable in response to insertion of a magnetic disk, a bail mounted on the housing base and angularly movable toward and away from the housing base in response to actuation of the cam body, and a magnetic head mounted on the housing base and movable toward and away from an operative position in response to movement of the bail. When the magnetic disk is not inserted, the magnetic head is positioned away from the operative position by the bail disposed away from the housing base by the cam body, and when the disk is inserted, the cam body is actuated to release the bail to allow the magnetic head to be moved to the operative position.