A display device, comprising: a substrate; a circuit layer over the substrate; a display layer over 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 (G1, G2) that surround the at least one hole, characterised in that: the substrate comprises a first substrate layer, a first inorganic layer, a second substrate layer, and a second inorganic layer, which are sequentially stacked, each of the at least two grooves (G1, G2) extends from the display layer down into the second substrate layer, the at least two grooves (G1, G2) comprise a first groove closest to the at least one hole and spaced apart from the at least one hole, and a second groove that surrounds the first groove and is spaced apart from the first groove, the second inorganic layer comprises a pair of first tips that extend into the first groove, wherein the pair of first tips face each other to form the undercut structure, the second inorganic layer comprises a pair of second tips that extend into the second groove, wherein the pair of second tips face each other to form the undercut structure, and the display device further comprises a bridge that connects the pair of second tips to each other along portions of the second groove, wherein the bridge is integrally formed with the pair of second tips, and the pair of first tips are spaced apart from each other along the entire first groove. a substrate; a circuit layer over the substrate; a display layer over 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 (G1, G2) that surround the at least one hole, characterised in that: the substrate comprises a first substrate layer, a first inorganic layer, a second substrate layer, and a second inorganic layer, which are sequentially stacked, each of the at least two grooves (G1, G2) extends from the display layer down into the second substrate layer, the at least two grooves (G1, G2) comprise a first groove closest to the at least one hole and spaced apart from the at least one hole, and a second groove that surrounds the first groove and is spaced apart from the first groove, the second inorganic layer comprises a pair of first tips that extend into the first groove, wherein the pair of first tips face each other to form the undercut structure, the second inorganic layer comprises a pair of second tips that extend into the second groove, wherein the pair of second tips face each other to form the undercut structure, and the display device further comprises a bridge that connects the pair of second tips to each other along portions of the second groove, wherein the bridge is integrally formed with the pair of second tips, and the pair of first tips are spaced apart from each other along the entire first groove. the substrate comprises a first substrate layer, a first inorganic layer, a second substrate layer, and a second inorganic layer, which are sequentially stacked, each of the at least two grooves (G1, G2) extends from the display layer down into the second substrate layer, the at least two grooves (G1, G2) comprise a first groove closest to the at least one hole and spaced apart from the at least one hole, and a second groove that surrounds the first groove and is spaced apart from the first groove, the second inorganic layer comprises a pair of first tips that extend into the first groove, wherein the pair of first tips face each other to form the undercut structure, the second inorganic layer comprises a pair of second tips that extend into the second groove, wherein the pair of second tips face each other to form the undercut structure, and the display device further comprises a bridge that connects the pair of second tips to each other along portions of the second groove, wherein the bridge is integrally formed with the pair of second tips, and the pair of first tips are spaced apart from each other along the entire first groove.