Abstract: Apparatus for on-line degassing and filtering aluminum and its alloys, constituted by a thermally insulated container body, provided with a removable lid (2) incorporating heating means (7) for heating the metal to be processed, said container body being internally subdivided, by means of a vertical partitioning wall (11) into two chambers communicating with each other only near the bottom of the container, wherein in one of said two chambers, provided with an inlet for the liquid metal to be processed, injection means (13, 14) are provided, for injecting inert, and/or active gases, which are so located as to perform a degassing in countercurrent relatively to the entering metal stream, while at the bottom of the second chamber at least a substantially horizontal plate, or wall (12) is provided, made of a porous material, such as ceramic, graphite, or the like, which is positioned spaced apart from the bottom of the container, such to allow the metal, coming from the first chamber, to flow upwards, and pass t