A filtering unit (10) comprising a casing (20) provided with at least one inlet (32), one outlet (33) and one support body (42) provided with
abutment surfaces (44) adapted to removably support a filtering
cartridge (50) contained within the casing (20) and adapted to divide the internal volume of the casing (20) into two chambers (21,22) respectively connected with the inlet (32) and the outlet (33) so as to filter the fluid flowing from the inlet (32) towards the outlet (33), the filtering
cartridge (50) comprising at least one
coupling element (55) configured to be snap-coupled to the support body (42) following a first axial translation for mutual approaching between the filtering
cartridge (50) and the support body (42), whose distinctive characteristic lies in the fact that it comprises
cam means (57,58) operating between the
coupling element (55) and the support body (42) so as to radially bend the
coupling element (55) in a release position for disengaging the coupling element (55) from the support element (42) following a further limited mutual axial translation between the filtering cartridge (50) and the support body (42), moving in the same direction with respect to the first approaching translation, the
cam means (57,58) being configured so as to keep the coupling element (55) in release position following a slight mutual rotation between the filtering cartridge (50) and the support body (42).