Abstract: Plant for filtering substances to be cleaned of various kind, particularly but not exclusively muds and other semi-solid or liquid dirty and polluting substances, constituted by one or more filtering devices (5) connected to each other, comprising a first circulation circuit of the substances to be cleaned introduced in to each filtering device (5) e for discharging the dirty and polluting substances after having been cleaned; a second circulation circuit of the cleaned liquids and the exit from the plant thereof, and the possible collection into suitable containers thereof; a third circulation circuit of suitable plant washing liquids, so as to clean the various plant component parts from the dirty and polluting substances remained after one or more working cycles.