The present invention efficiently arranges a spare TFT element in a pixel region of a liquid crystal display device. A display device includes a substrate on which TFT elements which are arranged in pixel regions each of which is surrounded by two neighboring scanning signal lines and two neighboring video signal lines are formed. The substrate arranges a first TFT element and a second TFT element in each pixel region in which the first TFT element and the second TFT element independently include a channel layer, a drain electrode and a source electrode respectively, only either one of the first TFT element and the second TFT element in each pixel region is operated when a video signal is applied to the video signal line and a scanning signal is applied to the scanning signal line, and the first TFT element and the second TFT element differ from each other in largeness or a shape of an occupied area or a channel width and a channel length of each TFT element when the substrate is viewed in a plan view.