A thin film transistor TFT substrate includes a substrate, a first conductive pattern that extends on the substrate in a first direction, a second conductive pattern located on the same layer as the first conductive pattern and nearest to a first side of the first conductive pattern in a second direction that is perpendicular to the first direction, and a dummy pattern located on the same layer as the first conductive pattern and located adjacent a second other side of the first conductive pattern which is opposite to the first side of the first conductive pattern.