Abstract: A device for automatic producing copies in accordance with a diffusion process from a two-sheet material includes a copy-receiving arrangement receiving exposed copies from a diffusion-developing device and having a plurality of flat copy-receiving surfaces positioned in a diffusion space for a full development of the copies being processed. Each copy is located on the respective copy-receiving surface so that no mutual displacement between the positive sheet and negative sheet of each copy takes place. Each copy is transported from the position at the entrance of the diffusion space to the position at the exit of the diffusion space in a step-like fashion. The ends of the copy-receiving surfaces are connected to a rotational transport device one after another in the endless belt-manner.