An image forming apparatus includes an image bearing member for carrying toner images of different colors; a rotatable intermediary transfer member to which the toner images are superimposedly transferred from said image bearing member onto said intermediary transfer member at a first transfer position, wherein the toner images are then transferred all together from said intermediary transfer member onto the transfer material at a second transfer position; wherein said intermediary transfer member includes an elastic layer having a thickness of 0.5-2 (mm), a coating layer, on said elastic layer, having a volume resistivity which is larger than that of said elastic layer, and said intermediary transfer member satisfies:T.ltoreq..tau..ltoreq.500 (sec)where .tau. (sec) is time required for a potential V of said intermediary transfer member at one second after a surface of said intermediary transfer member charged to a predetermined potential rotates at a rotational speed of 10 (cm/s) to become V/e (e: base of natural logarithm, e=2.71828 . . . ); and T (sec) is a rotation period of said intermediary transfer member when the toner images on said image bearing member are sequentially and superimposedly transferred onto said intermediary transfer member at the first transfer position.