A two-dimensional pattern of a silicon oxide film is formed on a silicon surface of a substrate, thereby to form a material, the two-dimensional pattern being represented by the presence and absence and/or thickness variations of the silicon oxide film. The material is nitrided to form a modified layer on the surface of the material, the modified layer being thicker on the silicon oxide film and thinner on the silicon surface of the substrate or thicker on the thicker portion of the silicon oxide film and thinner on the thinner portion of the silicon oxide film. The thinner portion of the modified layer is removed while leaving the thicker portion of the modified layer, for thereby forming the modified layer on the silicon oxide film substantially in the same shape as the silicon oxide film. An oxidant diffusion prevention film is formed at least on a thicker portion of the oxide film which has a thicker portion and a thinner portion on a substrate, then a silicon film, a silicide film, or a multilayer film composed of silicon and silicide films is deposited on a surface of the substrate a mask layer is formed on the film or films. The silicon film, the silicide film, or the multilayer film is oxidized to pattern the same in a shape corresponding to the mask layer. A relatively thin silicon oxide film may be formed on the oxidant diffusion prevention film.