A disk cartridge is provided that has an optical disk (2) encased therein. It includes a cartridge body (5) having formed therein a head opening (13) through which a part of the disk, ranging from the inner to outer radius, is exposed to outside, a shutter member (21) including a shutter (22) that covers and uncovers the head opening and installed to the cartridge body to be movable between a position to cover the head opening and a position to uncover the head opening, and shutter movement limiter (41) provided on an elastic moving piece (36) coupled to a coupling arm (35) extending from one side of the shutter member and that is engaged on a movement limiter (45) provided on the cartridge body, when the shutter member is in a position to cover the head opening, to limit the shutter member from moving in a direction of uncovering the head opening.