A technique to control segregation of impurities when reforming
crystallinity and crystallization of a semiconductor film by using a
laser beam irradiation is provided. The present invention is to irradiate
the substrate with applying ultrasonic vibration while keeping the end
portion of the substrate in space. The substrate on which a semiconductor
film is formed is kept onto the stage provided with opening pores, and
floated by spouting gas from opening pores. Supersonic vibration can be
efficiently provided to the substrate by irradiating with a laser beam
with ultrasonic vibration while keeping the end portion of the substrate.