PURPOSE:To minimize a wasteful copying and to shorten the time required for the recovery of paper clogging to the utmost by discharging copying form for one set from an intermediate tray to the outside of a copying machine when trouble occurred due to paper clogging during backside copying from the intermediate tray, and at the same time, making the recovery copy of the deficient one set of backside copy, housing it in the intermediate tray and then resuming the backside copying. CONSTITUTION:For instance, a both sides-both sides mode, a recycle mode, three sheets of original and three sets are assumed. In the process of surface copying, copied transfer form is housed once in an intermediate tray 133. When backside copying is started by paper feeding from the intermediate tray 133, and jamming occurred, the third sheet of the first set, the first sheet of the second set on the carrying path and the second sheet of the second set in the intermediate tray are discharged to the outside of the machine. In order to discharge to the outside of the machine, one set of deficient number is surface recovery copied and housed in the intermediate tray 133. Thereafter, the copying operation is continued regarding the third sheet of the second set as the third sheet of the first set by paper feeding from the intermediate tray 133.