An apparatus for processing photopolymer plates includes an exposure unit, a washing unit, and a drying unit. The plate, which has a water-developable photopolymer surface, is continuously conveyed through each unit so that the functions therein performed, are done automatically. More particularly, exposure is accomplished by bringing a negative photographic image into alignment with the water-developable photopolymer plate, and then passing light through the negative and onto portions of the plate. Unexposed areas of the plate are then washed away in the washing unit, thus producing a relief surface necessary for letter-press printing. Finally, the photopolymer plate is conveyed to the drying unit where drying and postcuring take place.