PURPOSE: To provide sufficient strength of a suitcase, and facilitate regeneration by providing inner wall parts wholly on the inner side of main body side surface parts and cover side surface parts on one side and on the other side, providing connection ribs at a specified interval in a double wall structure and inside edge parts of the double wall structure, and installing attachments to a suitcase main body and a cover body by fixing screws respectively.

CONSTITUTION: Inner wall parts 3 are provided wholly on the inner side of main body side surface parts 130, 140 on one side and on the other side, and cover side surface parts 230, 240 on one side and on the other side to form a double wall structure. Connection ribs 10 are provided at a specified interval in the double wall structure and inside edge parts 2 of the double wall structure. Attachments such as a side surface stopper 7 and an upper surface stopper 8 for detachably stopping a suitcase main body 100 and a cover body 200 to each other, and a handle 9 are installed by fixing screws from the inner surface side respectively. A sufficient strength as a suitcase can thus be provided, and the attachments can be removed easily to be regenerated and reused.