A display device includes: a substrate; a first insulating layer disposed on the substrate and that includes an inorganic insulating material; an oxide semiconductor layer disposed on the first insulating layer; a second insulating layer disposed on the oxide semiconductor layer and that includes an inorganic insulating material; and a third insulating layer disposed on a gate electrode disposed on the second insulating layer and that includes an inorganic insulating material. The oxide semiconductor layer includes a first conductive region, a second conductive region, and a channel region located between the first conductive region and the second conductive region, and a value in the channel region of the oxide semiconductor layer of HC according to equation (1) is less than 30%.