A semiconductor device capable of improving a device performance and a reliability is provided. The semiconductor device comprising a gate structure including a gate electrode on a substrate, a source/drain pattern on a side face of the gate electrode, on the substrate and, a source/drain contact connected to the source/drain pattern, on the source/drain pattern, a gate contact connected to the gate electrode, on the gate electrode, and a wiring structure connected to the source/drain contact and the gate contact, on the source/drain contact and the gate contact, wherein the wiring structure includes a first via plug, a second via plug, and a wiring line connected to the first via plug and the second via plug, the first via plug has a single conductive film structure, and the second via plug includes a lower via filling film, and an upper via filling film on the lower via filling film.