The semiconductor device includes a first MIS transistor including a gate insulating film 92, a gate electrode 108 formed on the gate insulating film 92 and source/drain regions 154, a second MIS transistor including a gate insulating film 96 thicker than the gate insulating film 92, a gate electrode 108 formed on the gate insulating film 96, source/drain regions 154 and a ballast resistor 120 connected to one of the source/drain regions 154, a salicide block insulating film 146 formed on the ballast resistor 120 with an insulating film 92 thinner than the gate insulating film 96 interposed therebetween, and a silicide film 156 formed on the source/drain regions 154.