Abstract: An active matrix liquid crystal display device includes a pixel transistor, a wiring layer, a first insulating layer, a lower electrode layer, a second insulating layer, and an upper electrode layer. The wiring layer is connected to the pixel transistor. The first insulating layer is provided on the pixel transistor and the wiring layer. The lower electrode layer is provided on the first insulating layer and used as one of a common electrode layer and a pixel electrode layer. The second insulating layer is provided on the lower electrode layer. The upper electrode layer is provided on the second insulating layer and used as the other of the common electrode layer and the pixel electrode layer. The thickness t of the second insulating layer satisfies t<[(?0?/W)×{(0.025381/P)2/6}]/(100×10?9) and t>[(?0?/W)×{(0.