To easily bore an ink refill hole in an ink cartridge by means of a small load by arranging an elastic member, which always energizes a fixing member to a grip part side, between a connecting member in the inside of an insertion hole and the fixing member in an ink refill hole boring member.

While an empty ink cartridge 2 inserted in a cartridge main body 1 is stored and fixed in a holder 3, an ink refill hole 5 is bored in the ink cartridge 2 by means of an ink refill hole boring member 4. In the holder 3, a projection part 8 provided with an opened hole 7, in which an internal thread part 6 is formed, is arranged in a part corresponding to the ink refill hole 5 boring position in the ink cartridge 2, while in the ink refill hole boring member 4, an elastic member 15 always energizing a fixing member 14 to a grip part 10 side is arranged between the fixing member 14, in which an external thread part to be screwed to the internal thread part 6 is arranged at the tip, and a connection member 11 in an insertion hole 12. Then, the grip part 10 and the drill 9 are connected and fixed together by means of the connecting member 11.