Abstract: An apparatus for electrolytically coating small parts, e.g. by electrophoretic deposition from a liquid coating agent, has a screw-type conveyor which can have a tube open at opposite ends to form an inlet and outlet for the parts which are advanced through the tube by screw conveyor means like a helical ribbon. The inlet side of the tube is immersed in a basin of the liquid coating agent whose side walls and front wall form weirs determining the level of the liquid coating agent in the tube while the liquid passes from the tube into a catch basin beyond the rear wall through perforations in the tube. The contacts traversing the tube wall are electrically-conductively coupled to the parts and are tied to one terminal of the DC power source whose other terminal is connected to a plate immersed in the dipping basin.