PURPOSE: To protect a bag body from damage by attaining the buffering of the whole of the bag body against the shock of vibration or falling, by providing a rigid member to the periphery of the ink take-out orifice of a flexible film bag and fixing a fixing member, which is provided separately from the take-out orifice so as to protrude toward the outside, to the fixing part of a cartridge case.

CONSTITUTION: A bag body 13 has an ink receiving bag 4 composed of a flexible film and a rigid member 14 to which the ink receiving bag 4 is thermally weldable. An ink take-out tube 5 having an elastic member 6 mounted thereto is mounted to the central part of the rigid member 14 in a pierced state and arm-shape mounting and fixing members 15 integrally molded along with the rigid member 14 are provided on both sides thereof in a protruding state. After the bag body 13 is mounted to a cartridge case so as to match the corresponding parts of the bag body 13 with the recessed part 12B and pins 12C of the cartridge case, an upper cartridge case is allowed to cover the bag body to weld the upper and lower cases. By this method, the ink take-out orifice part is not directly related to the support of the bag body 13 and vibration or a shock is buffered through the rigid member 14 to make it possible to sufficiently relieve the damage of the film itself or the damage to the welded part with the rigid member 14.