A semiconductor device includes a substrate including first and second active patterns thereon, a first gate electrode intersecting the first and second active patterns, first and second source/drain regions on the first and second active patterns, respectively, at one side of the first gate electrode, and an active contact on the first source/drain region so as to be electrically connected to the first source/drain region. The active contact includes a first sub-contact and a second sub-contact. The second sub-contact includes a vertical extension vertically extending toward the substrate. A bottom surface of the vertical extension is lower than a bottom surface of the first sub-contact.