The invention relates to a filter cartridge (1) comprising a filter medium (2) that is formed in such a way that it surrounds a central through-passage (3), wherein the central through-passage (3) has a first opening (4) and ends at a cartridge base (5), and wherein the filter medium (2) extends between the first opening (4) and the cartridge base (5) and thereby forms an elongated filter body, wherein, according to the object of the invention, to provide a filter cartridge which influences the average ascent speed of air and brings about an optimum filtration operation, the filter cartridge is characterised in that the filter medium (2) is rectangular or square-shaped at one end (6) of the filter cartridge (1) and is rounded at the other end (7).