Abstract: There is provided an apparatus for the filtration of fluid media, in particular for the pre-screening of media, that has a primary pack of hollow discs, which are arranged parallel to each other at regular distances to each other, the walls of which are made of a sieve material. The apparatus also has a primary, hollow shaft, which penetrates and is fixed to the hollow discs, connecting its interior to the cavities of the discs, and is fitted with a drive. Also included is a secondary pack of discs, which are arranged similarly to the hollow discs of the primary pack. There is a secondary shaft that is arranged similarly to the primary shaft. The two packs with their respective shafts are designed and arranged in such a way that the discs of one pack protrude into the spaces between neighboring discs of the other pack. There is a container that encloses the packs and the shafts. The container has an inlet for the medium to be treated, as well as an outlet for the retentate.