A filter insert (1) having an annular filter element (2) which is connected in a fluid-tight manner to a cover (5) on one axial end face (3) and to a base (6) on an opposite axial end face (4). The filter element (2) has a central channel (25) in which a central tube (8, 28) is situated. The central tube (8, 28) extends between the cover (5) and the base (6) and communicates with a central opening (7) in the cover (5). To ensure high stability of the filter (1) with a low manufacturing complexity, the central tube (8, 28) is designed to have a variable length in the direction of its longitudinal central axis (10).