An image forming apparatus, for ejecting liquid from openings to form an image on a printing medium, includes a head cap for covering the opening surface through which the openings open when a liquid ejection head in which the openings are formed is not in use and for protecting the openings from external air, a rechargeable battery for activating the image forming apparatus, a fuel cell for charging the rechargeable battery, and a liquid path along which water generated as the fuel cell is activated is introduced into the head cap. With this arrangement, when the liquid ejection head is not activated, the moisture retention in the head cap can be achieved.