A liquid crystal display unit in which at least one of a gate electrode line, a drain electrode line, and a gate electrode and a source/drain electrode of a TFT formed on a substrate is composed of a metal Nb or an alloy material of Nb. Glass is used as the substrate, and the size thereof is preferably 300 mm or longer on one side and 1 mm or less in thickness. In order to provide a low wiring resistance to produce a high resolution and large size TFT panel, the resistivity of the metal Nb or the alloy material thereof is preferably 25 .mu..OMEGA.cm or less, and the film stress of Nb or the alloy material thereof on the glass substrate is 400 MPa or less.