In order to suppress an off leak current of an off transistor for ESD protection, in an NMOS for ESD protection whose isolation region has a shallow trench structure, a drain region is placed apart from the shallow trench isolation region so as not to be in direct contact with the shallow trench isolation region in a region where the drain region of the NMOS transistor for ESD protection is adjacent to at least a gate electrode of the NMOS transistor for ESD protection.