A method for manufacturing thin film transistor array substrate for a liquid crystal display device-includes:—(a) forming a first metal thin film layer on a insulating substrate and forming a gate wiring and a gate electrode by a first photolithography. (b) forming a gate insulating film layer, a semiconductor film layer, an ohmic contact film layer and a second metal thin film layer, and forming the thin film transistor by a second photolithography, (c) forming an interlayer insulating film, and forming a pixel contact hole, a first contact hole and a second contact hole by a third photolithography, and (d) forming a transparent conductive film, and forming a pixel electrode by a fourth photolithography. The first metal thin film has a two-layered structure comprising a first layer made of aluminum or aluminum alloy and a second layer located on said first layer, and the second metal thin film is formed of an alloy mainly containing molybdenum.