Ni silicide is formed through simple steps. After forming a semiconductor film over a substrate, a Ni film is deposited over the semiconductor film while heating the substrate, thereby forming Ni silicide on the semiconductor film. Alternatively, after forming a semiconductor film over a substrate, a Ni film is deposited over the semiconductor film while heating the substrate up to 450° C. or higher, thereby forming Ni silicide on the semiconductor film. Alternatively, after forming a semiconductor film over a substrate, a Ni film is deposited with a thickness of 10 nm or more over the semiconductor film while heating the substrate to 450° C. or higher, thereby forming Ni silicide on the semiconductor film. Alternatively, after forming a semiconductor film over a substrate, and removing an oxide film on the semiconductor film, a Ni film is deposited over the semiconductor film while heating the substrate up to 450° C. or higher, thereby forming Ni silicide on the semiconductor film. Alternatively, after forming a semiconductor film over a substrate, and removing an oxide film on the semiconductor film, a Ni film is deposited with a thickness of 10 nm or more over the semiconductor film while heating the substrate up to 450° C. or higher, thereby forming Ni silicide on the semiconductor film.