To prevent a platen supported to a back cover or the like of a camera by slide structure, from sliding in the detached direction and to easily detach the platen.

A platen 10 supported to a back cover 2 of a camera is provided with engaging piece parts 102 in a plurality of places, and the back cover 2 is provided with support groove parts 23 in the positions corresponding to the engaging piece parts 102. The platen 10 is slid in the plane direction to engage the engaging piece parts 102 with the support groove parts 23. In such platen support structure, the platen 10 has an aperture 103 opened to insert through at least one screw 131 to be fastened to the back cover 2, and sliding of the platen 10 is impeded by abutting contact between the screw 131 and the inner surface of the aperture 103. The screw 131 in the aperture 103 of the platen prevents the platen 10 from sliding to release the engaged state of the engaging piece parts 102 and support groove parts 23, while the platen 10 slides to be detached from the back cover 2 only by detaching the screw 131, so that there is no need to detach other parts, thereby simplifying platen detaching work.