A cartridge 2 receiving a photosensitive recording disc 4 therein including: a cartridge body 11 having inner openings 18 and 19 exposing part of the recording disc 4 to the outside; a light-shield plate 12 attached to the outside of the cartridge body 11 and having outer openings 14 and 15 which face the inner openings 18 and 19; and a shutter 13 opening/closing the inner openings 18 and 19 and the outer openings 14 and 15 between the cartridge body 11 and the light-shield plate 12; wherein recesses 25e and 26e for inserting end edges 12d of the outer circumference of the light-shield plate 12 are provided in light-shield plate attachment surfaces 25a and 26a of the cartridge body 11 so that when the end edges 12d are inserted into the recesses 25e and 26e and attached to the cartridge body 11, a labyrinth-shaped light-shielding structure is formed.