Abstract: A filter device for a screw extruder for the handling of molten plastic comprising a filter housing having inlet and outlet bores and a slide displaceable in the housing transverse to the direction of the flow of the melt. At least one recess in the slide forms a portion of a melt channel and receives a screen member. In order to obtain uniform distribution of the flow of melt in the filter device and of the pressure forces acting on the filter surface, the recess is formed by an annular milling which is surrounded by a replaceable cylindrical screen member. A flow passage in the slide extends from the melt channel to the outlet bore.