An image forming device forms an image on a recording sheet by bidirectional recording. In the image forming device, a control part controls the image forming device. The control part includes a distance changing part that changes a sheet transporting distance for transporting the recording sheet after a forward movement of a recording head to a first transport distance and changes a sheet transporting distance for transporting the recording sheet after a backward movement of the recording head to a second transport distance, and a nozzle changing part that determines inactive nozzles which do not discharge a recording liquid among nozzles of the recording head alternately for one of the forward movement and the backward movement of the recording head.