A method is presented for making a polycrystalline thin film (B) by depositing particles emitted from a target (36) on a substrate base (A) to form the film (B) constituted by the target material while concurrently irradiating the depositing particles with an ion beam generated by an ion source (39) at an angle of incidence, in a range of 50 to 60 degrees to a normal (H) to a film surface, and maintaining a film temperature at less than 300 degrees Celsius. This method is effective in producing an excellent alignment of crystal axes of the grains in the film when the film thickness exceeds 200 nm. The target material includes yttrium-stabilized zirconia but other material can also be used. A layer (C) of a superconducting substance formed on top of the polycrystalline thin film (B) produces a superconducting film (22) exhibiting excellent superconducting properties.