A display device comprising: a display module in which a folding region (1000A2) that is folded with respect to a folding axis and first and second non-folding regions (1000A1, 1000A3) facing each other in the folded configuration with the folding region (1000A2) therebetween are defined; a heat dissipation sheet disposed on one surface of the display module, wherein the heat dissipation sheet comprises: a first heat dissipation adhesive layer comprising a first adhesive portion overlapping the first non-folding region (1000A1) and a second adhesive portion overlapping the second non-folding region (1000A3); a second heat dissipation adhesive layer comprising a third adhesive portion overlapping the first adhesive portion and a fourth adhesive portion overlapping the second adhesive portion; a heat dissipation layer comprising a first heat dissipation portion disposed between the first adhesive portion and the third adhesive portion and a second heat dissipation portion disposed between the second adhesive portion and the fourth adhesive portion; characterized by an auxiliary adhesive layer comprising a first auxiliary adhesive portion disposed between the first adhesive portion and the third adhesive portion to surround the first heat dissipation portion on a plane and a second auxiliary adhesive portion disposed between the second adhesive portion and the fourth adhesive portion to surround the second heat dissipation portion on the plane; wherein the first heat dissipation portion is sealed by the first adhesive portion, the third adhesive portion, and the first auxiliary adhesive portion, and the second heat dissipation portion is sealed by the second adhesive portion, the fourth adhesive portion, and the second auxiliary adhesive portion. a display module in which a folding region (1000A2) that is folded with respect to a folding axis and first and second non-folding regions (1000A1, 1000A3) facing each other in the folded configuration with the folding region (1000A2) therebetween are defined; a heat dissipation sheet disposed on one surface of the display module, wherein the heat dissipation sheet comprises: a first heat dissipation adhesive layer comprising a first adhesive portion overlapping the first non-folding region (1000A1) and a second adhesive portion overlapping the second non-folding region (1000A3); a second heat dissipation adhesive layer comprising a third adhesive portion overlapping the first adhesive portion and a fourth adhesive portion overlapping the second adhesive portion; a heat dissipation layer comprising a first heat dissipation portion disposed between the first adhesive portion and the third adhesive portion and a second heat dissipation portion disposed between the second adhesive portion and the fourth adhesive portion; characterized by an auxiliary adhesive layer comprising a first auxiliary adhesive portion disposed between the first adhesive portion and the third adhesive portion to surround the first heat dissipation portion on a plane and a second auxiliary adhesive portion disposed between the second adhesive portion and the fourth adhesive portion to surround the second heat dissipation portion on the plane; wherein the first heat dissipation portion is sealed by the first adhesive portion, the third adhesive portion, and the first auxiliary adhesive portion, and a first heat dissipation adhesive layer comprising a first adhesive portion overlapping the first non-folding region (1000A1) and a second adhesive portion overlapping the second non-folding region (1000A3); a second heat dissipation adhesive layer comprising a third adhesive portion overlapping the first adhesive portion and a fourth adhesive portion overlapping the second adhesive portion; a heat dissipation layer comprising a first heat dissipation portion disposed between the first adhesive portion and the third adhesive portion and a second heat dissipation portion disposed between the second adhesive portion and the fourth adhesive portion; characterized by an auxiliary adhesive layer comprising a first auxiliary adhesive portion disposed between the first adhesive portion and the third adhesive portion to surround the first heat dissipation portion on a plane and a second auxiliary adhesive portion disposed between the second adhesive portion and the fourth adhesive portion to surround the second heat dissipation portion on the plane; wherein the first heat dissipation portion is sealed by the first adhesive portion, the third adhesive portion, and the first auxiliary adhesive portion, and the second heat dissipation portion is sealed by the second adhesive portion, the fourth adhesive portion, and the second auxiliary adhesive portion.