PURPOSE: To obtain an excellent gettering effect by blocking the diffusion of oxygen to an epitaxial layer from a substrate.

CONSTITUTION: By conducting a nuclei forming heat treatment for formation of oxygen-deposited nuclei 6 after ion-implantation of impurities 2 into a silicon substrate 1, a surface layer 3, to be formed on the silicon substrate 1 and having a low density of injected impurities and a low density of deposited nuclei 6 is formed, a high density layer 4a, to be formed under the above-mentioned surface layer 3 and having high density of implanted impurities 2 and high density of deposited nuclei 6, is formed, and a low density region 5a, to be formed under the above-mentioned high density layer 4a and having the density of impurity 2 lower than the layer 4a and the density of deposited nuclei 6 lower than the layer 4a, is formed. Then, an epitaxial layer 8 is deposited on the surface layer 3.