The image forming apparatus comprises: an ejection head which forms an image on an ejection receiving medium, by ejecting liquid having electrorheological properties onto the ejection receiving medium; a holding device which holds the ejection receiving medium on a surface facing a liquid ejection surface of the ejection head; a conveyance device which conveys at least one of the ejection head and the ejection receiving medium held by the holding device relatively to each other in a conveyance direction; a first electrode group which includes at least a pair of a positive electrode and a negative electrode provided in the holding device, has a lengthwise direction coinciding with a sub-scanning direction substantially parallel to the conveyance direction of the conveyance device, and is disposed so as to be aligned with the main scanning direction substantially perpendicular to the sub-scanning direction; and a voltage supply device which supplies a prescribed voltage to the first electrode group.