A semiconductor device includes a first MIS transistor including a first gate electrode fully silicided with a metal. With the first MIS transistor includes: a first gate insulating film formed on a semiconductor region; the first gate electrode formed on the first gate insulating film; a first sidewall spacer formed on a side of the first gate electrode; and a second sidewall spacer formed at the side of the first gate electrode with the first sidewall spacer interposed therebetween; the first sidewall spacer and the second sidewall spacer have different etching characteristics. The first sidewall spacer has an upper end lower than an upper surface of the first gate electrode and an upper end of the second sidewall spacer.