Abstract: A device for an in-line filtering (10) of a liquid metal, by using only a single installation, to obtain a very good filtering of any liquid metal whatever its melting point. The device comprising a treating chamber (11) made of refractory material and having an inlet (12) for supplying the metal liquid to be filtered, an element for cleaning (16) the metal, and an element for degassing (17) the cleaned metal. The degassed metal is then injected, under pressure via an injection pump (18), into a porous filtering element (19) and injected liquid flows tangentially to a filtering surface of the filtering element (19) for filtering the metal while simultaneously cleaning the filtering surface. Under the effect of the applied pressure, a portion of the degassed metal passes through the filtering element (19), which is enclosed by a chamber (20), and the filtered liquid is evacuated through an output port (21) provided in the treating chamber (11).