PURPOSE: To produce an oxide superconductor composite by bonding an oxide superconductor layer firmly and uniformly to a metallic substrate.

CONSTITUTION: A paste of the calcined powder of an oxide superconductive material is applied on a metallic substrate and then heat-treated under specified conditions to produce an oxide superconductor composite consisting of the substrate and the oxide superconductor layer. In this case, 1-20wt.% of the paste is firstly applied on the metallic substrate, the inner layer of the superconductor is then formed by specified heat treatment, the remainder of the paste is applied on the inner layer and heat-treated to form the outer layer of the oxide superconductor, and an oxide superconductor layer is formed.