A semiconductor device including a driving region and a dummy region disposed at both side of the driving region includes a semiconductor substrate having a plurality of active regions spaced from each by equal distances in the driving region, a dummy active region in the dummy region, and a guard ring region surrounding the active regions and the dummy active regions. The distance between the dummy active region and the active region nearest to the dummy active region is substantially the same as each distance between adjacent ones of the active regions, and is smaller than the distance between the dummy active region and a portion of the guard ring region nearest to the dummy active region.