A foldable display device, comprising: a first support member and a second support member, which are separated from each other in a first direction; a display module disposed on the first support member and the second support member; a hinge extending in a second direction perpendicular to the first direction, and coupling one side of the first support member and one side of the second support member; a hinge cover surrounding the hinge on at least one side, wherein the hinge is disposed between the hinge cover and the display module in a third direction perpendicular to the first direction and the second direction; a first back cover disposed under the first support member in a direction opposite to the third direction, wherein an edge of the first back cover extending parallel to the one side of the first support member in the second direction is separated from the first support member in the direction opposite to the third direction, and wherein a first portion of the hinge and a first portion of the hinge cover are disposed between the first back cover and the display module when the display module is unfolded; a second back cover disposed under the second support member in the direction opposite to the third direction, wherein an edge of the second back cover extending parallel to the one side of the second support member in the second direction is separated from the second support member in the direction opposite to the third direction, and wherein a second portion of the hinge and a second portion of the hinge cover are disposed between the second back cover and the display module when the display module is unfolded; characterized in that the foldable display device further comprises: one or more dust caps (410, 420) disposed on at least one edge of the hinge cover; a first protrusion extending from the edge of the first back cover in the third direction; and a second protrusion extending from the edge of the second back cover in the third direction, wherein the first protrusion and the second protrusion contact a middle portion of hinge cover when the display module is unfolded, and the first protrusion and the second protrusion contact the one or more dust caps (410, 420) when the display module is folded. a first support member and a second support member, which are separated from each other in a first direction; a display module disposed on the first support member and the second support member; a hinge extending in a second direction perpendicular to the first direction, and coupling one side of the first support member and one side of the second support member; a hinge cover surrounding the hinge on at least one side, wherein the hinge is disposed between the hinge cover and the display module in a third direction perpendicular to the first direction and the second direction; a first back cover disposed under the first support member in a direction opposite to the third direction, wherein an edge of the first back cover extending parallel to the one side of the first support member in the second direction is separated from the first support member in the direction opposite to the third direction, and wherein a first portion of the hinge and a first portion of the hinge cover are disposed between the first back cover and the display module when the display module is unfolded; a second back cover disposed under the second support member in the direction opposite to the third direction, wherein an edge of the second back cover extending parallel to the one side of the second support member in the second direction is separated from the second support member in the direction opposite to the third direction, and wherein a second portion of the hinge and a second portion of the hinge cover are disposed between the second back cover and the display module when the display module is unfolded; characterized in that the foldable display device further comprises: one or more dust caps (410, 420) disposed on at least one edge of the hinge cover; a first protrusion extending from the edge of the first back cover in the third direction; and a second protrusion extending from the edge of the second back cover in the third direction, wherein the first protrusion and the second protrusion contact a middle portion of hinge cover when the display module is unfolded, and the first protrusion and the second protrusion contact the one or more dust caps (410, 420) when the display module is folded. one or more dust caps (410, 420) disposed on at least one edge of the hinge cover; a first protrusion extending from the edge of the first back cover in the third direction; and a second protrusion extending from the edge of the second back cover in the third direction, wherein the first protrusion and the second protrusion contact a middle portion of hinge cover when the display module is unfolded, and the first protrusion and the second protrusion contact the one or more dust caps (410, 420) when the display module is folded.