To be ready for the mass production and the automatic packaging by adhering a back side of a reinforcement piece extended from a margin piece to a base surface, returning a cover surface, attaching it to the margin piece and folding it, and erecting the cover surface to form a bellows of both side surfaces when a content is filled, and folding the reinforcement piece to form a reinforcement part.
In assembling a storage case, a part of a reinforcement piece 20 extended to a margin piece 19 is adhered to a base surface 11, and a cover surface 17 is lapped to the margin piece 19 and folded. In storing a content, a folded storage case is erected and developed, and at the same time, a center folding line (e) of a side surface 16 and a center folding line (g) of a side surface 18 are folded inward to form a bellows. The reinforcement piece 20 forms a U-shaped reinforcement part by reinforcement pieces 20a-20c with the margin piece 19 folded inward. A reinforcement structure of this shape not to be collapsed by the pressure from an upper part can be formed. A plate-like content consisting of a CD, etc., is inserted in a valley part opposite to the bellows, and held between ridges.
ABE YASUHIRO
SEKIGUCHI TAKESHI
