PURPOSE: To eliminate an erroneous copy of missing information, by detecting a size mark of overlay of a prescribed part, and selecting and feeding transfer paper of size corresponding to overlay by a controller in accordance with its detecting signal.

CONSTITUTION: An overlay device controlling circuit 106 operates a driving device 45 and a positioning detector 50 of an overlay device 2 by following the prescribed procedures, in accordance with a start command signal and an overlay designating signal from a CPU101, and executes positioning of the designated overlay. When this positioning has ended, a positioning end signal from a positioning detector 50-1 of the overlay device 2 and a picture size detecting signal from an overlay size detector 51 are inputted to the CPU101 through an I/O 104, respectively, a paper feed command signal is transferred to a copying machine body controlling circuit 107 so that transfer paper having the same size as picture size is fed, and the transfer paper having the same size as a picture is fed from a paper feeding device 16.