The purpose of the present invention is to provide a semiconductor device or a display device that can be manufactured by improving the use efficiency of a material as well as simplifying the manufacturing process, and a manufacturing technique of those devices. Also, another purpose of the present invention is to provide a technique for forming a pattern of wirings, etc., constituting the semiconductor device or the display device, in a desired shape and with good adhesiveness. The adhesiveness between first and second conductive layers is increased by forming a conductive buffer layer including at least one pore between them. The second conductive layer is formed by filling the pores of the buffer layer including at least one pore with a particle shaped conductive material which is solidified by baking. The conductive layer solidified in the pores functions like a wedge, and the second conductive layer is formed over the first conductive layer with good adhesiveness and stability.