A semiconductor device includes a substrate having an active region, a gate structure disposed on the active region, a source/drain region disposed in the active region at a side of the gate structure, a first interlayer insulating layer and a second interlayer insulating layer sequentially disposed on the gate structure and the source/drain region with an etch stop layer interposed therebetween, a first contact plug connected to the source/drain region through the first interlayer insulating layer, a second contact plug connected to the gate structure through the first interlayer insulating layer and the second interlayer insulating layer, a first metal line disposed on the second interlayer insulating layer, and having a metal via disposed in the second interlayer insulating layer and connected to the first contact plug, and a second metal line disposed on the second interlayer insulating layer, and directly connected to the second contact plug.