The semiconductor device which has a memory cell including the TMR film with which memory accuracy does not deteriorate, and its manufacturing method are obtained. A TMR element (a TMR film, a TMR upper electrode) is selectively formed in the region which corresponds in plan view on a TMR lower electrode in a part of formation area of a digit line. A TMR upper electrode is formed by 30-100 nm thickness of Ta, and functions also as a hard mask at the time of a manufacturing process. The interlayer insulation film formed from LT-SiN on the whole surface of a TMR element and the upper surface of a TMR lower electrode is formed, and the interlayer insulation film which covers the whole surface comprising the side surface of a TMR lower electrode, and includes LT-SiN is formed. The interlayer insulation film which covers the whole surface and includes SiO2 is formed.