A gas-filled discharge tube in which a cylindrical protection terminal is fitted to a gas-charging pipe passed through an electrode, and the electrode, the gas-charging pipe and the protection terminal are connected by electrical conductive binder filled in a clearance of these elements. A high-tension cable device in which at least one of a connector terminal or a power supplying terminal is formed with a concave part fitted, contacted with a connection part of an additional function parts such as a series-gap forming discharge tube. A high-tension cable device has a concave part covering an entire connection part of the additional function part and has a threaded part at an inner surface. An outer surface of the connection part of the function part corresponding to the concave part is formed with a threaded part.