A display device includes a substrate, a circuit layer on the substrate, a display layer on the circuit layer, at least one hole in a display area of the substrate that penetrates the substrate, the circuit layer, and the display layer, and at least two grooves that surround the at least one hole, where each of the at least two grooves has an undercut structure. The substrate includes a first substrate, a first inorganic layer, a second substrate, and a second inorganic layer, which are sequentially stacked, and each of the at least two grooves extends down from the display layer into the second substrate.