It is required that a line width of a wiring is prevented from being wider to be miniaturized when the wiring or the like is formed by a dropping method typified by an ink-jetting method. The invention provides a method for narrowing (miniaturizing) a line width according to a method different from a conventional method. One feature of the invention is that a plasma treatment is performed before forming a wiring or the like by a dropping method typified by an ink-jetting method. As the result of the plasma treatment, a surface for forming a conductive film is modified to be liquid-repellent. Consequently, a wiring or the like formed by a dropping method can be miniaturized.