An image forming apparatus includes: a transfer belt that is stretched on a plurality of support rollers including a backup roller in a loop-like manner and has an outer surface for carrying thereon a toner image; a transfer roller that is brought into pressurized contact with the backup roller across the transfer belt and forms a transfer nip with the transfer belt; a restriction member that is placed upstream of a transfer nip in a sheet conveying direction so as to be switchable between a first state in which the restriction member is brought closer to an inner surface of the transfer belt and a second state in which a distance of the restriction member from the inner surface of the transfer belt is larger than that in the first state; and a control section that switches a state of the restriction member.