Abstract: In a process for producing a high-temperature superconductor from oxides of bismuth, strontium, calcium, copper and optionally of lead and including sulfates of strontium and/or barium, the oxides of bismuth, strontium, calcium, copper and optionally of lead in the desired molar ratio, and from 2 to 30% by weight of strontium sulfate and/or from 1 to 20% by weight of barium sulfate, each calculated according to the mixture of the oxides, are mixed intimately, the mixture is melted in a crucible of a platinum metal at temperatures from 870.degree. to 1600.degree. C., the melt is poured into permanent molds of desired form and size and is allowed to solidify slowly therein, and the moldings produced are freed from the permanent mold material and are annealed for from 6 to 200 hours at temperatures from 700.degree. to 900.degree. C. in an oxygen-containing atmosphere.