Semiconductor device having a Damascene gate or a replacing gate

A semiconductor device includes semiconductor elements and at least one dummy pattern. Each or at least some of the semiconductor elements has a Damascene gate structure or a replacing gate structure and is located in element-forming regions. In addition, at least a dummy pattern is located in a region different from the element-forming regions. The dummy pattern may have a semiconductor element structure of the same or different kind from the Damascene gate structure or replacing gate structure. The dummy pattern may be a pattern of an insulating film, an interface transistor, or an analog circuit capacitor electrode instead of the dummy gate.