A filter element (10) is provided with open filter bellows (16) of a filter medium (18). The filter element (10) has at least one longitudinal mating surface (40) which is directed with at least one direction component axially to an element axis (14) of the filter element (10) and which is in contact with a corresponding longitudinal mating surface of the filter housing (11) for securing the filter element (10) axially to the element axis (14). The filter element (10) has at least one transverse retaining surface (52) which is directed with at least one direction component across the element axis (14). The transverse retaining surface (52) is separated from the at least one longitudinal retaining surface (40) and may be in contact with a corresponding transverse mating surface (56) of the filter housing (11) for securing the filter element (10) across the element axis (14).