A semiconductor device includes a substrate, first through fourth gate electrodes, and first through fifth fin active pattern. A first recess which is formed in the substrate between the first and second gate electrodes intersecting the second fin active pattern, is filled with a first source/drain region, and has a first depth in a third direction perpendicular to the first and second directions. A second recess which is formed in the substrate between the third and fourth gate electrodes intersecting the second fin active pattern, is filled with a second source/drain region, and has a second depth in the third direction. A third recess which is formed in the substrate between the second and third gate electrodes intersecting the second fin active pattern, is filled with a third source/drain region, and has a third depth in the third direction. The third depth is greater than the first and second depths.