Disc screen for separating solid residues, which includes multiple parallel rotation shafts, each of which carries a plurality of discs fixed thereto. In addition, the disc screen includes multiple shaped rings, which are each constituted by multiple sectors removably mounted around the rotation shafts, and they are placed between the discs in order to simply and easily vary the screening section. The external edge of each shaped ring is provided with thrust sections, which are adapted to intercept the material to be screened in order to subject the latter to a greater stress, which facilitates a more efficient separation of the materials, and push upward components of light and filamentous material so as to prevent possible entangling and obstructions of such materials at the rotation shafts.