Semiconductor device having a leading wiring layer

A manufacturing method of a semiconductor device, comprising the steps of forming an insulation layer, which has an opening section in an area including an area on an electrode pad, on a top surface of the semiconductor substrate on which the electrode pad is formed; at least forming a first barrier metal layer, which becomes a part of a leading wiring layer, in an inner peripheral surface of the opening section including the top surface of the electrode pad; at least forming a main conductor layer, which becomes a part of the leading wiring layer, in an area surrounded by the first barrier metal layer in the opening section; eliminating an upper portion of the main conductor layer at least to a position at which the first barrier metal layer is exposed, and forming a second barrier metal layer, which becomes a part of the leading wiring layer, so as to cover the whole top surface of the main conductor layer.