The transfer portion for use in an image forming apparatus includes: an intermediate transfer belt having a toner image temporarily transferred from a photoreceptor drum; roller members that support and stretch the intermediate transfer belt; and strip-like guide elements that guide conveyance of the intermediate transfer belt. The guide elements are provided on the inner peripheral surface of the intermediate transfer belt with the first and second ends opposed to and arranged a predetermined gap apart from each other. Each of the first and second ends is formed with a first (second) perpendicular surface that is perpendicular to the advancing direction of the belt and a first (second) inclined surface that is inclined relative to the belt advancing direction. The first and second perpendicular surfaces are formed in such a position that the first and second ends become tapered by the first and second inclined surfaces, respectively.