To provide an ink cartridge simple filling unit which is simple and can fill an ink cartridge with ink while keeping hands clean.

The ink cartridge simple filling unit 13 is composed of an ink bottle connector 16, a conducting pipe 17, and an ink cartridge connector 18. The ink cartridge connector inserts a plug at a distal end into a filling opening of the ink cartridge. The ink bottle connector has plugs to be respectively inserted and fitted in through holes 36 and 37 in an ink bottle cap 14 and is coupled thereto. When a syringe set at an ink outlet 27 of the ink cartridge sucks in inside air, the ink in the ink bottle is sucked into the ink cartridge. Excessive ink sucked into the syringe can be collected by setting the syringe at the opening at the top of the ink bottle connector inserted in the ink bottle cap and sucking it again.