Abstract: Disclosed is a processing unit with three treatment zones for photosensitive materials which are exposed imagewise, especially printing plates, comprising a housing top part which can be lifted off from a housing bottom part. Located on the housing top part are two separate run-in tables inclined obliquely downwardly which lead into feed slits. One run-in table can be folded against the front plate, whereas the other run-in table is integrated into the top side of the housing top part. Located on the rear side of the housing top part is a discharge slit with a run-out table inclined obliquely downwardly, which is equipped with an adjustable stop and which can be folded against the rear side of the processing unit. A heated air stream flows through an air outflow slit against the underside of the run-out table.