Semiconductor device

A semiconductor device includes a first-conductivity-type first MIS transistor and a second-conductivity-type second MIS transistor. The first and second MIS transistors include a first and a second gate insulating film formed on a first and a second active region surrounded by a separation region of a semiconductor substrate, and a first and a second gate electrode formed on the first and second gate insulating films. The first and second gate insulating films are separated from each other on a first separation region of the separation region. A distance s between first ends of the first and second active regions facing each other with the first separation region being interposed therebetween, and a protrusion amount d1 from the first end of the first active region to a first end of the first gate insulating film located on the first separation region establish a relationship d1