A cap film is formed over semiconductor films formed over an insulating substrate; the semiconductor films are irradiated with a laser beam which is capable of completely melting the semiconductor film in a film-thickness direction to completely melt the semiconductor film. By controlling the laser beam, a crystalline semiconductor films are formed over the substrate, in each of which orientations of crystal planes are controlled. In addition, an n-channel thin film transistor is formed using a crystalline region in which crystal planes are oriented along {001} and a p-channel thin film transistor is formed using a crystalline region in which crystal planes are oriented along {211} or {101}.