Abstract: A manufacturing method of a semiconductor device having a planar single crystal semiconductor surface is disclosed. In the manufacturing method of a semiconductor device, an insulating film is formed on a semiconductor substrate, a noncrystal semiconductor film is formed on the insulating film, a stripe-like anti-reflection film is formed on the noncrystal semiconductor film, and laser beam is irradiated along the anti-reflection film. Because of the difference in temperature, a film with thicknesses different in a substrate region in which the anti-reflection film is formed and a region around it is formed. A film to be a machining allowance for polishing is formed on the single crystal semiconductor film, polishing is performed from the side of said film to be a machining allowance for polishing so that desired planar film thickness of the single crystal semiconductor film is implemented.