Superconducting film-forming substrate, superconducting wire, and superconducting wire manufacturing method

A superconducting wire manufacturing method, comprising:

• a working process of working a superconducting film-forming substrate having a tape shape, the substrate comprising a film-forming face for forming a laminate including a superconducting layer thereon, a rear face that is a face at a side opposite to the film-forming face, a pair of end faces connected to the film-forming face and the rear face, and a pair of side faces connected to the film-forming face and the rear face, so as to shape a spreading face that spreads toward an outer side in an in-plane direction of the film-forming face from an edge part of the film-forming face toward the rear face side, on each of the pair of side faces;
• an intermediate layer forming process of forming an intermediate layer on the film-forming face of the superconducting film-forming substrate and on at least the spreading face on the pair of side faces, after the working process;
• and
• a superconducting layer forming process of forming a superconducting layer on a surface of the intermediate layer.