A second sealing film F2 is thermally bonded onto a leading end portion R1 of an ink lead-out member 32b of an ink pack and an annular projecting portion R2 provided on an ink casing 31. Thereby, a gap D produced between the ink lead-out member 32b and the ink casing 31 can be closed from outside the ink casing 31. Accordingly, the airtightness of a space S in the ink casing 31 is kept, thus making it possible to raise the pressure in the space S and generate such a force as to crush the ink pack.