The invention provides a display device and a manufacturing method thereof. The manufacturing method of the display device including a gate electrode film, a first electrode film, a second electrode film, and a conductive film connected to the first electrode film and formed of a conductive layer including a first conductive layer and a second conductive layer formed overlapping the first conductive layer. The method includes the steps of forming the first electrode film and the second electrode film, forming the conductive layer such that the conductive layer is connected to the first electrode film and the second electrode film, and forming the conductive film by removing regions other than predetermined regions of the conductive layer, wherein the conductive layer forming step includes the steps of forming the first conductive layer on the respective upper surfaces of the first electrode film and the second electrode film and forming the second conductive layer on the upper surface of the first conductive layer.