According to one embodiment, a method of manufacturing a metal silicide layer, the method includes forming a metal layer including impurities on a silicon layer by a vapor deposition method using a gas of a metal and a gas of the impurities, and forming a metal silicide layer including the impurities by chemically reacting the metal layer with the silicon layer. A thickness and a composition of the metal silicide layer are controlled by an amount of the impurities in the metal layer.