A disk cartridge includes a case body that is capable of housing a plurality of disk-shaped recording media and is joined or separated by making a first shell contact with/separate from a second shell in an axial direction, and a lock lever that is rotatably supported and locks the first shell and the second shell in a joining manner, in the inside of the case body. A supporting shaft is provided to the case body, the lock lever includes a supported part and a lock part, a disk inserting/ejecting slot is formed, an open/close panel is provided to the first shell, the lock lever is supported on an end part of the case body, and an insertion concave part in which the lock part of the lock lever can be inserted and engaged is formed within an inner face of the open/close panel.