Medical infusion filter with optimized filling

A medical infusion filter (1) comprises a box body (2) defined by at least two half shells (3, 4) coupled together to define an internal cavity (7) divided into at least two chambers (8, 9) by at least one hydrophilic filtering membrane (5), these chambers comprising at least one first or entry chamber (8) and at least one second or exit chamber (9), the at least one first or entry chamber (8) being connected to an entry conduit (10) for the medical fluid originating from a corresponding container and the at least one second or exit chamber (9) being connected to an exit conduit (11), at least the first or entry chamber (8) provided within a first half shell (3) presenting at least one aperture (13, 14) within which a corresponding hydrophobic membrane (16, 17) is positioned. The at least one aperture (13, 14) enables a differential air flow rate to pass towards the exterior of said box casing (2) as a function of the distance of the casing air exit zone from the entry conduit.