A disk cartridge includes a case body that can house 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 disk inserting/ejecting slot is formed, a supporting shaft is provided to the case body, the lock lever includes a supported part, a lock part, and a lock-release part, the first shell is provided with an open/close panel that includes an insertion hole, an insertion protrusion part that is inserted into the insertion hole of the open/close panel is provided to an end part of the lock-release part, and an end face of the insertion protrusion part is formed as an inclined face.