A patterning process comprising the steps of: forming on a substrate an organic underlayer film, a silicon-containing middle layer film thereon, and further an upper layer resist film thereon; subjecting the upper layer resist film to exposure and development to form an upper layer resist pattern; transferring the upper layer resist pattern to the silicon-containing middle layer film by dry etching using the upper layer resist film having the formed upper layer resist pattern as a mask, and further transferring the upper layer resist pattern to the organic underlayer film by dry etching using the silicon-containing middle layer film having the transferred upper layer resist pattern as a mask to form an organic underlayer film pattern; forming an inorganic silicon film by a CVD method or an ALD method so as to cover the organic underlayer film pattern; removing a portion of the inorganic silicon film by dry etching to expose an upper portion of the organic underlayer film pattern; and removing the organic underlayer film pattern with a stripping liquid to form an inorganic silicon film pattern whose pattern pitch is 1/2 of that of the upper layer resist pattern, characterized in that the silicon-containing middle layer film is formed from a composition for forming a silicon middle layer, the composition containing a compound having a crosslinking organic structure, the organic underlayer film contains any of a fluorene skeleton-containing compound, a carbazole skeleton-containing compound, an acenaphthylene skeleton-containing compound, a naphthol skeleton-containing compound, and a bisnaphthol skeleton-containing compound, and the inorganic silicon film is made of polysilicon, amorphous silicon, silicon oxide, silicon oxynitride, silicon carbide, or a composite material thereof. forming on a substrate an organic underlayer film, a silicon-containing middle layer film thereon, and further an upper layer resist film thereon; subjecting the upper layer resist film to exposure and development to form an upper layer resist pattern; transferring the upper layer resist pattern to the silicon-containing middle layer film by dry etching using the upper layer resist film having the formed upper layer resist pattern as a mask, and further transferring the upper layer resist pattern to the organic underlayer film by dry etching using the silicon-containing middle layer film having the transferred upper layer resist pattern as a mask to form an organic underlayer film pattern; forming an inorganic silicon film by a CVD method or an ALD method so as to cover the organic underlayer film pattern; removing a portion of the inorganic silicon film by dry etching to expose an upper portion of the organic underlayer film pattern; and removing the organic underlayer film pattern with a stripping liquid to form an inorganic silicon film pattern whose pattern pitch is 1/2 of that of the upper layer resist pattern, the silicon-containing middle layer film is formed from a composition for forming a silicon middle layer, the composition containing a compound having a crosslinking organic structure, the organic underlayer film contains any of a fluorene skeleton-containing compound, a carbazole skeleton-containing compound, an acenaphthylene skeleton-containing compound, a naphthol skeleton-containing compound, and a bisnaphthol skeleton-containing compound, and the inorganic silicon film is made of polysilicon, amorphous silicon, silicon oxide, silicon oxynitride, silicon carbide, or a composite material thereof.