PURPOSE: To produce the Bi-based oxide superconducting material having a uniform composition at the time of producing a Bi, Pb, Ca, Sr, Cu and O-based superconducting material by mixing a Bi, Pb, Cu and O-based intermediate and a Ca, Sr, Cu and O-based intermediate, pelletizing the mixture and sintering the pellet in an oxidizing atmosphere.

CONSTITUTION: Powdery Bi2O3, PbO and CuO are uniformly mixed in Bi:Pb:Cu=1:0.2:1, and the mixture is calcined at 750°C for 10hr in an oxidizing atmosphere to produce an intermediate shown by BiPb0.2CuO2.7. Powdery SrCO3, CaCO3 and CuO are mixed in Se:Ca:Cu=1:1:1, and the mixture is calcined at 1000°C in an oxidizing atmosphere to produce an intermediate shown by CaSrCuO3. Both intermediate are disintegrated and thereafter mixed in Bi:Pb: Sr:Ca:Cu=1:0.2:1:1:2, the mixture is again calcined, disintegrated and pelletized, and the pellet is sintered in an oxidizing atmosphere. Consequently, an oxide- based superconducting material having ≥77K critical temp. is obtained.