Abstract: The overvoltage suppressor has a cylindrical active part, which is arranged between two electrically conductive, cylindrical fittings and contains at least one varistor on a metal-oxide base, as well as an insulating material housing which surrounds the active part and is closed at the ends by the fittings. The insulating material housing is filled with an insulating material which surrounds the active part on the outside and is formed by an injection-molded or extruded insulating material tube and by a shielded weather protection which is held on the outer surface of the tube. A first of the two fittings is integrally formed into the tube at a first of its two ends. An external thread on the second fitting is screwed into an internal thread in the tube, forming a contact force.