In a manufacturing process of a semiconductor device, electroplating and CMP have had a problem of increase in manufacturing costs for forming a wiring. Correspondingly, an opening is formed in a porous insulating film after a mask is formed thereover, and a conductive material containing Ag is dropped into the opening. Further, a first conductive layer is formed by baking the conductive material dropped into the opening by selective irradiation with laser light. Subsequently, a metal film is formed over the entire surface by sputtering, and the mask is removed thereafter to have only the metal film remain over the first conductive layer, thereby forming an embedded wiring layer formed with a stack of the first conductive layer containing Ag and the second conductive layer (metal film).