A semiconductor device includes a first MISFET and a second MISFET which are formed over a semiconductor substrate and have the same conductive type. The first MISFET has a first gate insulating film arranged over the semiconductor substrate, a first gate electrode arranged over the first gate insulating film, and a first source region and a first drain region. The second MISFET has a second gate insulating film arranged over the semiconductor substrate, a second gate electrode arranged over the second gate insulating film, and a second source region and a second drain region. The first and the second gate electrode are electrically coupled, the first and the second source region are electrically coupled, and the first and the second drain region are electrically coupled. Accordingly, the first and the second MISFET are coupled in parallel. In addition, threshold voltages are different between the first and the second MISFET.