A semiconductor device includes a substrate, an isolation structure, a first gate structure, a second gate structure, a first slot contact structure, a first gate contact structure, and a second gate contact structure. The substrate includes a first active region and a second active region elongated in a first direction respectively. The first gate structure, the second gate structure, and the first slot contact structure are continuously elongated in a second direction respectively. The first gate contact structure and the second gate contact structure are disposed at two opposite sides of the first slot contact structure in the first direction respectively.