To provide a method of manufacturing a semiconductor device and an annealing apparatus, capable of forming a semiconductor element from a good quality semiconductor film by setting lamp annealing conditions to match changes in optical characteristics, during the crystallization of a non- crystalline semiconductor film.

After forming a semiconductor film 100 made of an amorphous silicon film on a substrate 50 formed of glass or the like with a low-temperature process (film-forming process), lamp annealing is performed to thereby make the film 100 polycrystalline (crystallization process). In the latter process the film 100 is irradiated with, a first lamp light L11 (whose energy is 1.6 eV or higher and whose wavelength is 700 nm or shorter), having optimal energy in terms of the band gap of the amorphous silicon (film 100), and thereafter it is irradiated with a second lamp light L12 (whose energy is 1.1-1.6 eV and wavelength of 700-1,130 nm or higher), having energy which can be absorbed by the film 100 in terms of the band gap of the amorphous silicon (film 100).