A display panel comprising: a substrate; a conductive pattern formed on the substrate; an insulating layer formed on the conductive pattern;a gate line which is formed on the substrate and extends substantially in a first direction; a data line which is insulated from the gate line and extends substantially in a second direction; a thin film transistor (G1, G2, ACT, S, D) which is electrically connected to the gate line and the data line; and a pixel electrode which is electrically connected to the thin film transistor, wherein the thin film transistor comprises: a gate electrode which is formed on the insulating layer; a gate insulating film which is formed on the substrate and the gate electrode; an active layer which is formed on the gate insulating film to at least partially overlap the gate electrode; and a source electrode and a drain electrode which are formed on the active layer and the gate insulating film so as to be spaced apart from each other, wherein the conductive pattern comprises at least one of aluminum and silver, and the gate electrode comprises copper, characterized in that the display panel further comprises a polarizing plate positioned between the substrate and the gate line, wherein the polarizing plate is a wire grid polarizing plate which includes a plurality of parallel conductive wire patterns, wherein the wire grid polarizing plate further includes an electrically insulating protective film positioned between the conductive wire patterns and the gate line, and wherein the protective film comprises a structure in which an SiOC layer is sequentially laminated on an SiOx layer. a substrate; a conductive pattern formed on the substrate; an insulating layer formed on the conductive pattern;a gate line which is formed on the substrate and extends substantially in a first direction; a data line which is insulated from the gate line and extends substantially in a second direction; a thin film transistor (G1, G2, ACT, S, D) which is electrically connected to the gate line and the data line; and a pixel electrode which is electrically connected to the thin film transistor, wherein the thin film transistor comprises: a gate electrode which is formed on the insulating layer; a gate insulating film which is formed on the substrate and the gate electrode; an active layer which is formed on the gate insulating film to at least partially overlap the gate electrode; and a source electrode and a drain electrode which are formed on the active layer and the gate insulating film so as to be spaced apart from each other, a gate electrode which is formed on the insulating layer; a gate insulating film which is formed on the substrate and the gate electrode; an active layer which is formed on the gate insulating film to at least partially overlap the gate electrode; and a source electrode and a drain electrode which are formed on the active layer and the gate insulating film so as to be spaced apart from each other, wherein the conductive pattern comprises at least one of aluminum and silver, and the gate electrode comprises copper, characterized in that the display panel further comprises a polarizing plate positioned between the substrate and the gate line, wherein the polarizing plate is a wire grid polarizing plate which includes a plurality of parallel conductive wire patterns, wherein the wire grid polarizing plate further includes an electrically insulating protective film positioned between the conductive wire patterns and the gate line, and wherein the protective film comprises a structure in which an SiOC layer is sequentially laminated on an SiOx layer.