PROBLEM TO BE SOLVED: To provide a novel forming method to mass-produce a fine structural pattern of nm order with excellent reproducibility.
SOLUTION: A resist film 3 is formed on one main surface 2A of a substrate 2. The resist film 3 is irradiated with an X-ray 4 through a mask 1 for X-ray exposure to form an exposure pattern 5. By developing the resist film 3, the exposure pattern 5 is selectively removed to form a resist pattern 6. A work 7 formed of a vacuum ultraviolet ray absorbing material is formed on the main surface 2A of the substrate 2 so as to cover the resist pattern 6. A vacuum ultraviolet ray area of the work 7 is irradiated with electronic synchrotron radiation 8 having the wavelength peak in the vacuum ultraviolet ray zone to precipitate a decomposed metal film. The resist pattern 6 is removed to form a fine structural pattern 10 in which a precipitated metal film 9 is deposited between the pitches of the resist pattern 6.