Abstract: A superconductive conductor or cable comprising a core, which comprises at least one string of a ceramic, superconductive material, and where the core is encapsulated by a metal cap. In order to manufacture a conductor or a cable with an encapsulation, and in which it is possible as well during the manufacturing process as under the operation to maintain a controlled atmosphere around the superconductive core, at least one layer of not sintered, ceramic powderous material is provided between the cap and the core, which material has a higher sintering temperature than the superconductive material in the core. The superconductive core may be sintered for formation of the superconductive ceramics by placing in the tubular metal cap a starting material in powderous form, and shaped as a core in the other ceramic powder material and subsequently forgeing the the metal cap with its content, preferably by swaging at an ambient temperature, which is below the sintering temperature of the core.