A method of manufacturing a liquid crystal display device having a substrate with a display area, a control area adjacent to the display area, and terminals. The method includes forming an interlayer insulating film and an a-Si film below an image signal line in the display area and below a line in the same layer as the image signal line in the control area, forming a scribing line outside the terminals, forming a ground line in the same layer as the scan line outside the scribing line, forming the interlayer insulating film outside the terminal, without forming the a-Si film on the interlayer insulating film, forming a static electricity protection line coupled to the terminal on the interlayer insulating film, the static electricity protection line being coupled to other static electricity protection lines outside the ground line, and, after the steps above, separating the substrate along the scribing line.