Disclosed is a method of manufacturing semiconductor devices, in which a monocrystalline thin film is formed by dissolving and recrystallizing either amorphous or polycrystalline thin film by annealing with energy beams, comprising the steps of: forming a compound film of a belt-shaped high melting point metal having a width narrower than the diameter of said energy beams and polycrystalline silicon, on said amorphous or polycrystalline thin film; causing said amorphous or polycrystalline thin film to contact with a monocrystalline substrate beneath the center line of said belt-shaped compound film at a position of more than 50 to 200 .mu.m remote from the end of the belt-shaped compound film in the scanning direction of said energy beams, with the contact shape being a tiny spot narrower than the width of the belt-shaped compound film; radiating said energy beams, penetrating through said belt-shaped compound film to scan parallel to the belt, starting from the vicinity of the end of the belt-shaped compound film, and inducing crystal growth of the amorphous or polycrystalline thin film beneath the belt-shaped compound film, starting from the monocrystals inheriting the crystalline configuration of the monocrystalline substrate developed by epitaxial growth from the monocrystalline substrate in the amorphous or polycrystalline thin film contacting with the monocrystalline substrate near the end of the belt-shaped compound film.It is more preferable to compose so that the upper surface of the amorphous or polycrystalline thin film contacting with the monocrystalline substrate may be flush with the upper surface of the amophous or polycrystalline thin film not contacting with the monocrystalline substrate near this contacting portion.