A filter device for the clarification of contaminated liquids includes a plurality of disk-shaped filter elements spaced apart from one another and combined into circular or polygonal filter modules. The filter elements are arranged rotatably about a horizontal axis in a vessel containing the unclarified liquid. The filtrate is capable of being discharged via the individual filter modules. The filter modules form centrally a cavity. The cavity on one side is closed by a carrying disk and on the other side is connected to the vessel via a suction-intake orifice. The cavity is connected operatively to a flow member in such a way that, via the suction-intake orifice, a flow can be generated in the unclarified liquid between the spaced-apart filter elements and avoids an adhesion of solids to the filter elements.