PURPOSE: To form a thin film made of a laminated body of group IIa -group IIIa-copper/oxide by evaporating group IIa, group IIIa metals and copper in sequence and in turn, laminating them on a substrate, and radiating an oxygen neutral beam on the substrate during the deposition of them.

CONSTITUTION: The group IIa metal end/or its oxide, group IIIa metal and/or its oxide, and copper and/or its oxide are evaporated in sequence or copper and/or its oxide and other two kinds of metals and/or their oxides are evaporated in turn and laminated on a substrate. In addition, an oxygen neutral beam is radiated on the substrate during the deposition of them. That is, metals or metal oxides are driven into a metal or metal oxide substrate or into other deposition object already stuck on the substrate by this oxygen neutral beam, a mixing layer is formed on their interfaces to firmly bind with the substrate and between layers, and the peel strength is improved. A superconductive thin film made of a laminated body of the group IIa-group IIIa-copper/oxide is thereby formed on the substrate.