A tandem image forming unit is provided with an adhering substance removal mode for performing a cleaning operation of a photoreceptor and an intermediate transfer body at the time other than the time of image formation. In the adhering substance removal mode, a photoreceptor cleaning unit removes excess toner from the photoreceptor. An intermediate transfer body cleaning unit removes excess toner from the intermediate transfer body. Therefore, the adhering substance removal mode can be performed simultaneously with respect to the photoreceptor and the intermediate transfer body.