An image forming apparatus capable of reproducing in different colors a plurality of image areas selected from a plurality of different originals on a single copy sheet.The apparatus comprises a transparent original holder device on which is placed an original in such a way that the image bearing surface of said original faces downwardly; a first original placement reference indicating device disposed on the transparent original holder device; an original pressure device which is movable between a first position at which the original pressure device covers the transparent original holder device and a second position at which the original pressure device opens the transparent original holder device; an image area designation device which is disposed on the surface of the original pressure device and on which is placed an original with the image bearing surface thereof faced upwardly so as to designate an image area to be copied of the original; a second original placement reference indicating device which is disposed on the surface of the original pressure device and is provided for the image area designation device; and a scanning device for exposing and scanning the original placed on the transparent original holder.