A display device and manufacturing method thereof with a high level of reliability is provided without increasing the number of manufacturing processes. The display device includes a first conductor, a first insulation layer including a first contact hole exposing a part of the first conductor, a second insulation layer including a second contact hole exposing at least a part of the first contact hole and a part of a surface of the first insulation layer, a pixel electrode overlapping a part of the second contact hole and electrically connected to the first conductor, and a third insulation layer contacting the first insulation layer via the second contact hole.