a filter element for filtering liquids or gases , having a concentrically arranged filter medium with zigzag pleats . the filter medium is provided with end disks on its axial end faces , each end disk having an inside that is connected to the filter medium and an outside that faces away from the filter medium . at least a first end disk carries a valve element which is situated concentrically inside the filter medium . this valve element includes a valve seat which bulges outward above the plane of the outer side of the end disk . the valve element includes a valve body which cooperates with the valve seat and which is arranged on the first end disk so that it is axially movable and is inside of and surrounded by the filter medium .