Abstract: A magnetic separator for removing contaminations from a liquid to which a ferromagnetic particulate material has been added is formed of a plurality of discs arranged along a shaft parallel to each other with spaces therebetween, the bottom parts of which dip into a container for the liquid. The discs contain permanent magnets of substantial coercive field strength over at least the greater part of their areas. The ferromagnetic material and contaminants carried thereby are scraped off the surface of the discs by belts which surround the shaft and which extend outside the discs to discharge the material scraped off of the discs.