PROBLEM TO BE SOLVED: To provide a CVD device and a film forming method for superconducting thin film that can stably form a superconducting thin film on a surface of a tape-shaped substrate while suppressing temperature variation in a film formation region due to a shield gas.SOLUTION: A CVD device 1 forms a superconducting thin film on a surface of a tape-shaped substrate 50 through chemical reaction by supplying a raw material gas to the surface of the tape-shaped substrate 50 traveling right above a susceptor 13 in a reaction chamber 10. The reaction chamber 10 includes: a shield gas jet part 25 which includes a first shield plate 12 partitioning the inside of the reaction chamber 10 into a film formation region A2 to which the raw material gas is supplied and a substrate introduction region A1 located upstream from the film formation region A2 in a travel direction of the tape-shaped substrate 50, and jets the shield gas toward the susceptor 13 so as to suppress diffusion of the raw material gas from the
