In an infrared ray sensor for a bolometer, a bridge structure body, a resistive element film for the bolometer, and a protection film is formed via a space on a substrate, and is formed into a solution form by dissolving metal organic compound into solvent. The solution is applied and dried. A laser ray is irradiated for the solution with wavelength of 400 nm or less. A bond between carbon and oxygen is decomposed and cut to thereby form an oxide thin-film.