Filtering device, especially for use as a well screen filter

The present invention relates to filtering device which is especially designed for use as a well screen filter. The filtering device comprises a tubular supporting element (12) and two or more tubular segments (14) of a porous filter medium arranged in axial alignment to one another and concentrically and essentially coextensive with the tubular supporting element (12), said tubular supporting element (12) having a tubular wall provided with a plurality of perforations (26, 28, 30) and having a plurality of projections projecting from said tubular wall, said projections supporting the two or more tubular segments in axial alignment with the tubular wall, said tubular segments each having two end portions which are in sealing contact with the tubular supporting element or an end portion of another tubular segment.