A fuse has a fuse element (6) with a fusible conductor (7) of a conductor material (8) such as Ag, Cu or Al and is provided with doping points (9) following one another at regular intervals. There, the conductor material (8) has a directly adjoining layer of a first compound (10) of the same with a doping material such as In or Ge. It forms mixed crystals which contain the conductor material (8) and the doping material in a fixed stoichiometric ratio, such as for example Ag2In, and is separated from said conductor material by a stable phase boundary. The doping points (9) weaken the fusible conductor by lowering the melting point to below 250° C., so that arc formation rapidly occurs there when there are short-circuit currents, although its electrical resistance per unit of length is under some circumstances only a few percent greater than in the remaining region. The fusible conductor (7) bears a continuous layer of a burn-up material (12). It has an ignition temperature which is preferably lower than the melting point of the first compound (10).