A disc cartridge includes: a disc medium; a case formed by an upper shell and a lower shell; a first aperture formed in the case; an inner rotor rotatably accommodated in the case and having a second aperture that has substantially the same size as the first aperture; a pair of shutter members supported between the inner rotor and the lower shell, being pivotable around their axes to open or close the first aperture and the second aperture; a guide hole formed in each of the shutter members; guide projections provided at the lower shell, the guide projections respectively passing through the guide holes and, along with rotation of the inner rotor, causing the shutter members to pivot around their axes to open or close; and recessed portions formed in the inner rotor to avoid contact with tips of the guide projections passing through the guide holes.