Abstract: A tubular filter element has a filtering material extending over a whole length and having in its interior a hollow chamber so that during a filtering operation the filtering material is loaded from outside with a medium to be filtered which passes through the filtering material from outside inwardly to the hollow chamber, a back wash aid arranged in the hollow chamber, a coaxial inner tube located in the hollow chamber of the filtering material and arranged at least at some locations with a distance from the filtering material so as to form at least one intermediate chamber, the inner tube having a tubular wall and being provided at least substantially in a lower longitudinal region with throughgoing passages extending through the tube wall and formed so that, for back washing of the filtering material a back washing medium is supplied opposite to a filtering operation on the one hand into an interior of the inner tube and through the throughgoing passages and on the other hand also into the at least one int