A p-channel MOS transistor includes a gate electrode formed on a silicon substrate via a gate insulating film, a channel region formed below the gate electrode within the silicon substrate, and a p-type source region and a p-type drain region formed at opposite sides of the channel region within the silicon substrate. In the p-channel MOS transistor, first and second sidewall insulating films are arranged on opposing sidewall faces of the gate electrode. First and second p-type epitaxial regions are respectively formed at outer sides of the first and second sidewall insulating films on the silicon substrate, and the first and second p-type epitaxial regions are arranged to be higher than the gate electrode. A stress film that stores tensile stress and covers the gate electrode via the first and second sidewall insulating films is continuously arranged over the first and second p-type epitaxial regions.