PURPOSE: To prevent an ink from leaking from an ink-containing member, by returning a seal film member to an original shape thereof by an elastic member when a hollow member is drawn out from the ink-containing member.

CONSTITUTION: A seal film 34 provided at a joint cover part 14 of an ink cartridge part 12 is constituted of, for example, a laminate of a thin polyethylene film 30 and a thin aluminum film 32, and is flexible. An elastic member 38 is adhered to the seal film 34. When fitting the ink cartridge part 12 to a printing head part 8, a tip part T of an ink-supplying pipe 20 is inserted into an ink-supplying pipe receiving part 40, and is pushed further inward, whereby the tip part T is made to penetrate through the seal film 34, while breaking only a seal film region contacted thereby. Thus, an ink 36 is fed to a head plate 2 through an ink-supplying part 20. When the ink cartridge part 12 is detached (drawn out) from the head part 8, the seal film 34 is closed by a recoil strength of the elastic member 38, thereby preventing the ink 36 from leaking out.