Ink cartridge and method of making an ink cartridge.

An ink cartridge comprising: a cartridge main body (2) having a storage chamber ink (11), an atmospheric open chamber (501) and a hole atmospheric communication (60) for communicating the storage chamber ink and the atmospheric open chamber (501) together; and an atmospheric open valve (601) having a valve body (65) capable of opening and closing the hole atmospheric communication (60) of said cartridge main body (2), and an elastic member (62) capable of pressing the valve body (65) in a closing direction, wherein: the elastic member (62) presses, at one end, the valve body (65) in the closing direction, and is fixed in a part opposite end, into the atmospheric open chamber (501).