A metal line in a semiconductor device and fabricating method thereof includes a first contact plug on a substrate, a first insulating interlayer over the substrate including the first contact plug, a first etch stop layer formed over the first insulating interlayer; a trench in the first insulating interlayer and the first etch stopper layer, a metal line in the trench, the metal line including a second contact plug projecting from the trench, wherein the metal line and the trench are formed as a single body, and a second insulating interlayer over the substrate including the metal line and the second contact plug.