Upon occurrence of a paper jam on a main conveying route, a controller performs control of stopping paper conveyance at a section of the main conveying route upstream of a position of the paper jam in a conveying direction and discharging sheets at a section of the main conveying route downstream of the position of the paper jam in the conveying direction, and performs control of stopping paper conveyance at a circulation conveying route. Upon occurrence of a paper jam on the circulation conveying route, a controller performs control of stopping paper conveyance at a section of the circulation conveying route upstream of a position of the paper jam, and performs control of discharging sheets at a section of the circulation conveying route downstream of the position of the paper jam and at the main conveying route.