A semiconductor device includes first and second active regions extending in a first direction on a substrate and spaced apart from each other in a second direction intersecting the first direction, wherein the first and second active regions overlaps with each other in the second direction, a third active region extending in the first direction on the substrate and spaced apart from the first active region in the second direction. The first active region is positioned between the second and third active regions in the second direction. The first and third active regions partially overlap in the second direction, and a device isolation film is configured to define the first to third active regions.