An impurity region is formed on the surface of a semiconductor substrate. An insulating layer is provided on the semiconductor substrate to cover the impurity region. A trench for defining a wiring layer is provided on the surface of the insulating layer. A connection hole is provided in the insulating layer for connecting the trench and the impurity region with each other. A conductive layer made of a high melting point metal or a compound thereof is embedded in the connection hole. A copper wire is formed in the trench to be connected to the conductive layer. According to the present invention, a semiconductor device improved to be capable of implementing an excellent wiring circuit and providing a highly integrated semiconductor circuit is obtained.