An image forming apparatus includes a plurality of image bearing members to bear a toner image on a surface thereof, a transfer device including a plurality of transfer members and an endless belt formed into a loop and entrained around the transfer members, to transfer the toner images from the image bearing members onto the surface of the belt so that the toner images are superimposed one atop the other on the belt to form a composite toner image, a plurality of cleaning devices including a cleaning blade to remove residual toner remaining on the image bearing members after transfer of the toner images onto the belt, and a plurality of heaters disposed inside the loop formed by the belt. Each of the heaters is disposed between adjacent image bearing members. The belt is interposed between the plurality of heaters and the plurality of image bearing members.