A filter element (1) for an air filter (30) has a tubular filter medium (2), the annular cross-section of which encloses an interior (6) of the filter element and which has an inner wall (7) that adjoins the interior of the filter element and that extends in the form of at least one convex arch (8) and at least two concave arches (9), the concave arch (9) being located between two convex arches (8) such that the interior (6) of the filter element has a constriction (11) in the area of the concave arch (9), the constriction (11) being adjoined by two wide zones (12) of the interior of the filter element.