An image forming apparatus includes a toner image forming device to form a toner image on a rotatable toner image bearer, a looped belt to carry a recording medium, a support roller to rotate the belt, a pressing member to press the belt against the toner image bearer, a transfer electric field generator to form an electric field to transfer the toner image onto the recording medium, and a contact member to contact an end surface of the belt as the belt moves to one side in a belt width direction. The belt includes a first portion pressed against the toner image bearer by the pressing member and a second portion adjoining the first portion. A relative position of the support roller relative to the toner image bearer and the pressing member is determined such that the second portion of the belt contacts the toner image bearer.