The present invention provides a display device which can obviate the occurrence of a leak current in a thin film transistor. In a display device including a substrate, and gate signal lines, an insulation film, semiconductor layers and conductor layers which are sequentially stacked on the substrate, the conductor layer forms at least a drain electrode which is connected to a drain signal line and a source electrode which is connected to a pixel electrode, and the semiconductor layer is formed in a pattern in which the semiconductor layer has a protruding portion which protrudes outwardly from the conductor layer at a portion thereof except for a distal end of the drain electrode as viewed in a plan view.