An object of the invention is to provide a semiconductor device and a display device which can be manufactured with improved material efficiency through a simplified manufacturing process, and a manufacturing method thereof. Another object is to provide a technique capable of forming a pattern such as a wiring included in the semiconductor device or display device in a desired shape with good controllability. One feature of a method for manufacturing a semiconductor device is to comprise the steps of forming a layer having a rough surface, forming a region having low wettability by a composition containing a conductive material and a region having high wettability by the composition over the rough surface, and forming a conductive material using the composition in the region having high wettability. Since regions having largely different wettability (regions having a large difference in wettability) can be formed, a liquid conductive or insulating material is attached only to a formation region with precision. Accordingly, a conductive or insulating layer can be precisely formed in a desired pattern.