A method of removing a phosphorus-doped silicon film doped with phosphorus, includes: forming a silicon oxide film by oxidizing the phosphorus-doped silicon film in a substrate including the phosphorus-doped silicon film and an undoped silicon film which is not been doped with the phosphorus, wherein at least the phosphorus-doped silicon film is exposed to a surface of the substrate; and selectively etching and removing the silicon oxide film from the silicon oxide film and the undoped silicon film.