The invention relates to a screw press for separating liquids from a suspension, in particular a sludge or fibrous-material suspension, having at least one worm shaft (2) that rotates in a cylindrical casing (1), wherein the suspension is pressed through an annular gap (3) formed between the casing (1) and the worm shaft (2) from at least one inlet opening (4) to an outlet opening (9) and the casing (1) consists at least of a radially internal screen (5) and a radially external support body (6). In this case, high stability coupled with a weight of the support body (6) that is as low as possible is intended to be achieved without impairment of function in that the support body (6) is formed at least from a plurality of axially spaced-apart support rings (7) that are oriented perpendicularly to the axis, the support rings (7) are connected together via a plurality of axially extending support rods (8) that are arranged in a manner distributed around the circumference of the support rings (7), at least the support rods (8) are sectionally in contact with the screen (5) and at least a plurality of support rods (8) have cutouts (10) and/or apertures between these contact sections close to the screen (5).