A device for processing a porous filtration medium has a holding part that can be mounted on a lower part with the porous filtration medium. An outer wall of the holding part can be positioned outside a surface, of the filtration medium, and a fixing edge arranged in the holding part can be positioned on an edge of the filtration medium. The holding part has a filtration support which, on its side facing away from the filtration medium, is connected to an outlet for reverse flushing.