An image forming device which includes a first nozzle group, a second nozzle group, and are arranged by being deviated from the first nozzle group to one side in a predetermined direction, a light irradiation unit which is extended at least in the predetermined direction, a control unit which repeats an ejection operation in which the photo-curable ink is ejected from the nozzle while moving the nozzle group and the light irradiation unit in a direction intersecting the predetermined direction, and a transport operation of the medium in a state where a non-ejection region where the ink is not ejected is provided between the first nozzle group and the second nozzle group in a predetermined direction, and overlappingly forms a main image using the first photo-curable ink, and a background image using the second photo-curable ink.