PURPOSE: To make it unnecessary to turn an original inside out twice, to prevent jam of the original, and to enhance the reliability of operation, by using the copying paper inversion device of the output part of an automatic both-side copying device.

CONSTITUTION: An original (b) is placed on the tray 5 of an automatic circulation type both-side original feeder (AHD). A paper route changeover mechanism 17, a both-side copy tray 16, and the like prescribed copying system are made ready for automatic both-side copying. The originals are exposed in the order of the first page and the second page of the first original, and processed as shown in the figure II→III→IV, and returned on the tray with the second page down. The second and the following originals are treated likewise, and after copying the whole, the separator 9 contacts a sensor 26, and the second copying start signal is produced. At that time, the first original is copied in the order of the second page and the first page, and returned in a posture same as the initial posture. In this second copying, the paper route changeover device 20 of an inverter 22 is changed over so as to send the copying paper not to an inverter, but to a sorter.