It is made possible to reduce the interface resistance at the interface between the nickel silicide film and the silicon. A semiconductor manufacturing method includes: forming an impurity region on a silicon substrate, with impurities being introduced into the impurity region; depositing a Ni layer so as to cover the impurity region; changing the surface of the impurity region into a NiSi2 layer through annealing; forming a Ni layer on the NiSi2 layer; and silicidating the NiSi2 layer through annealing.