A method of manufacturing a semiconductor device comprises: (a) loading a substrate into a process chamber, wherein the substrate has at least a silicon exposure surface and an exposure surface of silicon oxide film or silicon nitride film on a substrate surface; (b) simultaneously supplying at least a first process gas containing silicon and a second process gas for etching into the process chamber under conditions that the substrate inside the process chamber is heated to a predetermined temperature; and (c) supplying a third process gas having a stronger etchability than the second process gas into the process chamber, wherein the operation (b) and the operation (c) are performed at least one or more times so that an epitaxial film is selectively grown on the silicon exposure surface of the substrate surface