A display device for improving an aperture ratio of the pixel is provided. In the display device, a transparent oxide layer, an insulating film, and a conductive layer are sequentially stacked on a pixel region on a substrate, the conductive layer has a gate electrode of a thin film transistor connected to a gate signal line, and a region of the transparent oxide layer other than at least a channel region portion directly below the gate electrode is converted into an electrically conductive region, and a source signal line, a source region portion of the thin film transistor connected to the source signal line, a pixel electrode, and a drain region portion of the thin film transistor connected to the pixel electrode are formed from the conductive region.