Reliability of a semiconductor device is improved. The semiconductor device includes a silicon pattern for a fuse element, a metal silicide layer formed on an upper surface and a side surface of the silicon pattern, a gate electrode for MISFET, and a metal silicide layer formed on an upper surface of the gate electrode. The height from the lower surface of the silicon pattern to the lower end of the metal silicide layer is lower than the height from the lower surface of the gate electrode to the lower end of the metal silicide layer.