Abstract: The present invention relates to a fastener means for securing a center conductor (23) in a cavity filter and for enabling the center conductor to be secured mechanically in a stable fashion and with good electric contact between itself and the bottom 22 of the cavity. The inventive fastener means comprises a center conductor and a fastener element (25, 26) provided integral therewith to form a single-piece structure, which structure may have the form of a screw with the center conductor (23) as the screw head at one end and screw threads (26) at the other end. The contact surface between the fastener means and the cavity bottom is surface-treated with a material of low resistivity, such as silver for example.