The device for dehumidifying and compacting solids contained in sewage for disposal, is designed to be applicable to machinery (1) comprising: a tubular screen (2) having at least an inlet (4) for a product to be separated, at least an outlet (5) for a separated solid part, and at least a filtering wall (3) through which the separated liquid part exits; a transport organ (7) predisposed internally of the screen (2) for transporting the solid part to be compacted towards the outlet (5). The device comprises a contrast element (9), predisposed at the outlet (5) for interacting contactingly with the product, which in a rest position thereof occupies at least a part of a mouth of the outlet (5) and which, under an effect of a pushing action of the product to be compacted, can elastically deform in order to increase a size of a free mouth of the outlet.