To improve attachable/detachable property to/from a disk holding part by forming a pair of lids via hinges on the right and left of a back wall formed with the holding part for housing a disk such as an FD and by forming the holding part out of a pair of sidewalls for holding the disk from both sides.

The storage case 1 comprises a plate-like back wall 2 extending in a rectangular form at the center and a pair of left and right lids 3, 4 connected to the left and right of the back wall 2 via hinges 5, 5, wherein when the lids 3, 4 are closed, one peripheral wall 32 and the other peripheral wall 42 align with each other, and a protruding stage 32a and a recessed stage 42b are locked on an internal wall side. In this case, a pair of holding parts 20 are formed at both longitudinal ends of the back wall 2. Each of the holding parts 20 comprises a pair of sidewalls 21 extending along a longitudinal direction of the back wall 2 and a connection wall 22 for connecting both sidewalls 21, 21 at external ends of the side wall 21, wherein a base of a surface of a disk can be held from both sides between the pair of sidewalls 21, 21.