Provided is a semiconductor device including active regions formed in a semiconductor substrate and arranged in a first direction parallel to a surface of the semiconductor substrate; a first element isolating region formed in the semiconductor substrate and electrically isolating adjacent active regions from each other; and gate electrodes extending over the active regions respectively and arranged in the first direction. The first element isolating region includes a first region extending in a second direction orthogonal to the first direction and a second region extending in a direction intersecting the first region, one gate electrode of adjacent gate electrodes has a first edge side which includes a first overlap part placed on the second region, and another gate electrode of the adjacent gate electrodes has a second edge side which faces the first edge side and includes a second overlap part placed on the second region.