PURPOSE: To execute both side copying by providing a copying machine with 2 transfer devices for the same photosensitive body, transferring a toner image on the surface of a copying paper in one of the devices, and transferring a toner image on the reverse side of it after inverting said image transferred and fixed paper in the other device.

CONSTITUTION: A copying paper 3 fed from an upper paper feed stand 2 undergoes the transfer of a toner image at the first transfer device 11.13, fixed with the first fixing device 21, then, inverted, and placed on a lower paper feed stand 4. The copying paper 5 having finished the surface copying is again fed from the stand 4 and undergoes the transfer of another toner image on the reverse side at the second transfer device 12.14, fixed with the second fixing device 22, and ejected to an ejection tray 6.