A semiconductor device is provided in which ESD is less likely to occur in a manufacturing process thereof. In manufacture of a semiconductor device including a long lead wiring A, during steps with direct exposure to a plasma atmosphere, a plurality of island-shaped wirings is formed for the wiring A and then electrically connected to one another in series. Specifically, a plurality of island-shaped wirings is formed, covered with an insulating layer, and electrically connected to one another in series by a wiring formed over the insulating layer. The island-shaped wiring and the wiring formed over the insulating layer are electrically connected to each other through an opening formed in the insulating layer.