A semiconductor device includes an integrated circuit and a guard ring. The integrated circuit includes a first circuit and a second circuit separated from the first circuit. The guard ring is disposed around the first circuit and between the first circuit and the second circuit. The guard ring includes an outer ring, an inner ring, and two connectors. The outer ring is disposed around the first circuit and has a first gap. The inner ring is disposed between the outer ring and the first circuit and has a second gap. The two connectors connect the outer ring and the inner ring. The outer ring, the inner ring, and the two connectors form a closed loop.