PURPOSE: To provide the manufacturing method, of a semiconductor film, in which a polycrystalline semiconductor film can be formed at a temperature which is lower than that in conventional cases.

CONSTITUTION: An amorphous silicon film 4 which contains a crystal phase 3 is deposited on a glass substrate 2 by a plasma CVD method. Hydrogen 5 is contained in the amorphous silicon film 4. Then, a heat treatment is executed by using a heater 6 or the like. The hydrogen 5 in the amorphous silicon film 4 is dissociated by the heat treatment. Then, silicon 7 is ion-implanted; the crystal phase 3 is grown. The silicon film 4 which has been amorphous is grown to a polycrystalline silicon film 9 which contains crystal particles 8. Since the hydrogen in the amorphous silicon film is dissociated, the growth of the crystal phase is not suppressed, and a polycrystalline semiconductor film can be formed at a temperature which is lower than that in conventional cases.