The invention relates to a method of removing metals from metal-charged waste sludges from industry, clarification plants, or the like, in which the sludges are treated with a solvent for the metals, the resulting solution is separated from the undissolved substances and worked up to yield the metals, and the remaining solids are dumped as safe waste materials or used as fertilizers. The invention also relates to an apparatus for carrying out this working-up method, characterized by a mixing apparatus for mixing the solvent and the sludge which is to be treated, a residence zone, an adjoining apparatus for separating the metal-charged solvent from the insoluble fraction, and optionally an apparatus for drying the insoluble fraction. Metal sludges can be continuously worked up, if desired, in the apparatus according to the invention.