In a semiconductor device, an insulating interlayer is provided above a semiconductor substrate, and a plurality of first wiring layers and a plurality of second wiring layers are formed in the insulating interlayer. The first wiring layers are substantially composed of copper, and are arranged in parallel at a large pitch. The second wiring layers are substantially composed of copper, and are arranged in parallel at a small pitch. A first metal capping layer is formed on each of the first wiring layers, and a second metal capping layer is formed on each of the second wiring layers. The second metal capping layer has a smaller thickness than that of the first metal capping layer.