PURPOSE: To obtain a superconductor capable of exhibiting superconductivity, especially at liquid N2 temperature or above, by firing a compact of a blended powder of Y oxide powder, Ba hydroxide power and Cu oxide powder in an oxidizing atmosphere.

CONSTITUTION: Powder of an Y oxide (Y2O3) is thoroughly mixed with powder of Ba hydroxide [Ba(OH)2] and powder of Cu oxide (CuO) in a ball mill, etc. The resultant blended powder is then filled in a metallic mold and compacted under about 700kg/cm2 pressure to provide a compact, which is then placed in a firing device and fired at about 1,050°C temperature in an oxidizing atmosphere for several hour to afford the aimed superconductor consisting of a sintered compact. The above-mentioned sintered compact is required to consist of Y, Ba, Cu and O and have composition ratios of 10≤Y≤60atom.%, 20≤Ba≤50atom.% and 30≤Cu≤65atom.% in Y-Ba-Cu. The superconductor of this invention completely attains a superconducting state at liquid N2 temperature (77K).