Disclosed are a method for forming a silicon thin-film on a substrate, and more particularly a method for forming a polycrystalline silicon thin-film of good quality on a flexible metal substrate. A metal substrate (110) is prepared and a surface of the metal substrate (110) is flattened. An insulation film (120) is formed on the metal substrate (110). An amorphous silicon layer (130) is formed on the insulation film (120). A metal layer (140) is formed on the amorphous silicon layer (130). A sample on the metal substrate (110) is heated and crystallized.