PURPOSE: To decrease wiring resistance and to solve problems such as deficient contrast and deficient resolution when a titled substrate is used for a liquid crystal display device by forming source line into two-layered structure.

CONSTITUTION: A thin semiconductor film 101 consisting of polycrystalline silicon, etc. is formed to an island shape on the insulating substrate 100 and a gate insulating film 101' by thermal oxidation, etc., is formed thereon. A gate wiring 102 and the 1st layer of a source line 102' are then formed by polycrystalline silicon, etc. having an impurity of an H-type (or P-type) and thereafter, a source.drain region is formed by an ion implantation method, etc. An inter-layer insulating film 103 consisting of HSG, PSG, etc. is formed over the entire surface and a contact hole 104 is formed on the source.drain region and the 1st layer of the source line. A picture element electrode 105' and the 2nd layer of the source line 105 are finally formed of a transparent conductive film of ITO, etc.