A method of manufacturing a semiconductor device includes alternately performing supplying a first process gas containing silicon and a halogen element to a substrate having a surface on which monocrystalline silicon and an insulation film are exposed and supplying a second process gas containing silicon and not containing a halogen element to the substrate, and supplying a third process gas containing silicon to the substrate, whereby a first silicon film is homo-epitaxially grown on the monocrystalline silicon and a second silicon film differing in crystal structure from the first silicon film is grown on the insulation film.