Cartridge accommodating case

A cartridge accommodating case comprising:

• a cartridge accommodating upper case having a partitioned chamber formed therein for holding a cartridge group formed into a block as a plurality of flat body-shaped cartridges, in each of which a reel with a magnetic tape wound therearound is disposed, are juxtaposed in a thicknesswise direction thereof;
• and
• a cartridge accommodating lower case having a partitioned chamber of a shape substantially identical to that of the partitioned chamber of the cartridge accommodating upper case, the partitioned chamber of the cartridge accommodating lower case being formed at a position opposing the partitioned chamber of the cartridge accommodating upper case;
• a partitioned chamber of an expanse which is twice as large as the partitioned chamber being formed in an interior of the cartridge accommodating case by superposing on each other the upper case and the lower case which respectively have a protruding portion and a recessed portion for mutual engagement and are of a same structure, and by engaging the protruding portion and the recessed portion,
• wherein a detour portion which is spaced apart a distance from a ridge line of the cartridge accommodated in the cartridge accommodating case is formed so as to form a space portion on an inner side of the detour portion in an area surrounding the ridge line.