A manufacturing method of a superconducting material having the steps of: milling and mixing a powderly primary material in a casing of a dry type milling mixer; heat-processing the primary material obtained from the milling/mixing step; and again milling and mixing the primary material obtained from the heat-processing step in the casing of the milling mixer so as to obtain a secondary material. The milling mixer includes a casing for holding the primary material therein and friction-pulverizing mixing elements for frictionally pulverizing, stirring and mixing the primary material inside the casing. The two milling/mixing steps are effected under a high-speed rotation of the casing where a centrifugal force resulting from the casing rotation presses the primary material against an inner surface of the casing and a layer of the material formed on the surface is frictionally pulverized, stirred and mixed by the friction-pulverizing mixture elements.