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<[(.epsilon..sub.0.epsilon./W).times.{(0.025381/P).sup.2/6}]/(100.tim- es.10.sup.-9) and t>[(.epsilon..sub.0.epsilon./W).times.{(0.025381/P).sup.2/6}.times.k.t- imes..rho..sub.ON]/.tau..sub.ON, where a display pixel has a substantially square shape and is composed of a plurality of sub pixels, a pitch at which the display pixels are arranged vertically and a pitch at which the display pixel are arranged horizontally are respectively P per 25.381 mm, the channel width of the pixel transistor is W, the on resistance per unit channel width of the pixel transistor is .rho..sub.ON, a period of time during which a gate line and drain line of the pixel transistor are simultaneously turned on is .tau..sub.ON, a relative dielectric constant of the second insulating layer .epsilon., a vacuum dielectric constant is .epsilon..sub.0, a correction parameter is k. Liquid crystal molecules are driven by applying voltage between the upper electrode layer and the lower electrode layer.