To easily know a correct direction of insertion into a recorder/player and assure a large width of an access opening through which the optical head approaches an optical disc, a disc cartridge is provided which includes an access opening (21) formed in a cartridge body (6) and through which a part of the recording area of an optical disc (5), extending between lead-in and lead-out areas, is exposed outside for data read and write, a pair of shutter members (25), (26) provided movably towards and away from each other to open and close the access opening (21); and a shutter open/close mechanism (27) having a pair of guide recesses (36a) and (36b) formed in a main side the of the cartridge body (6) obliquely in relation to the width of the cartridge body (6) to support the pair of shutter members (25) and (26), respectively, to be movable.