PURPOSE: To readily grow a Bi Sr Ca Cu O-based superconductor on a substrate, with good reproducibility by mixing Bi2O3 with SrCO3, CaCO3 and CuO in a specific proportion, calcining the resultant mixture, heating and evaporating the obtained source.

CONSTITUTION: Bi2O3 is mixed with SrCO3, CaCO3 and CuO at 1:(3-15):(4-30):(2-5) molar ratio and the resultant mixture is then calcined at about 850°C in the open air. The calcined mixture is subsequently pulverized, remixed, then compacted and formed into a pellet-like shape, which is further calcined at 850°C in the air. A superconductor consisting of Bi Sr Ca Cu O is then formed from a source consisting of the above-mentioned calcined mixture on a substrate with electron beams. In the afore-mentioned method for production, the amounts of the SrCO3 and CaCO3, having a lower vapor pressure than that of other raw materials and hardly evaporable are increased to supply the insufficiency and attain the above-mentioned object.