Infusion filter operating effectively in various spatial positions

A filter (1) for filtering a fluid directed towards a patient, comprising a box casing (2) in which at least one cavity (37) is present defined by an outer element (3, 4) of said casing (2) and an inner surface (5A, 5B) presenting a plurality of channels (21) on which a corresponding hydrophilic filtering membrane (30) lies, said cavity (37) communicating with a conduit (27) for entry of the fluid into the filter (1) and said channels (21) being connected to a conduit (23) for exit of said fluid from the filter (1), in said element (3, 4) of the box casing (2) there being provided spaced-apart through apertures (40, 41) close to its opposing ends (42, 43) and with which hydrophobic membranes (44) are associated, characterised in that a surface (S1) bounded by an ideal closed line (70), which totally comprises all the hydrophobic membranes (44), contains substantially within its interior the projection thereon of the useful hydrophilic surface (S2) of the hydrophilic filtering membrane (30), this enabling the filter (1) to be employed in a plurality of spatial positions during its use.