In a step F2, an isolation region and an element formation region are formed in an SOI substrate. In a step F3, an SOI region and a bulk region are formed. Here, an isolation insulating film of the isolation region is exposed along the entire perimeter of a sidewall of a step between the SOI region and the bulk region. In a step F4, a gate electrode is formed. In a step F5, extension implantation of a bulk transistor is carried out. Here, treatment for preventing an impurity for extension implantation from being implanted into the SOI region is performed. In a step F6, an elevated epitaxial layer is formed in the SOI region.