The image forming apparatus comprises: an ejection head which includes a plurality of nozzles to eject a liquid to deposit the liquid on a recording medium being conveyed relatively to the ejection head to form an image on the recording medium; a tank which stores the liquid to be supplied to the nozzles and has an adjustable internal pressure; a liquid supply path which connects the tank and the ejection head; a cap which faces a nozzle face on which the nozzles of the ejection head are formed; a liquid collection path which is capable of connecting the cap and the tank; and a liquid circulating device which is provided on the liquid collection path, collects the liquid in the ejection head through the cap, circulates the liquid to the tank along the liquid collection path, and adjusts the internal pressure of the tank to a desired value.