A method for thermally spraying a film on an inner face of a bore of a cylinder block. A pair of suction pipes generates a spiraling air current in the bore, creating an air flow toward the center of the bore. A spraying device sprays molten metal partaicles including fumes toward the inner face of the bore. The fumes are captured by the spiraling air current and removed from molten metal particles directing toward the inner face of the bore. Molten metal particles from which the fumes are removed form the thermally sprayed film on the inner face of the bore. High-quality thermally sprayed film scarcely containing fumes can be formed on the inner face of the bore.