A curved display device is disclosed. In one aspect, the display device includes a substrate comprising a flat portion and at least one curved portion, a display unit comprising a first display area on the flat portion, and a second display area on the curved portion, and a thin-film encapsulating layer sealing the display unit, and comprising at least one organic layer and at least one inorganic layer. The display device also includes a functional layer over the thin-film encapsulating layer, wherein the thin-film encapsulating layer comprises a first region overlapping the curved portion, and a second region overlapping the flat portion. The inorganic layer contacts the functional layer, and wherein the inorganic layer has a first surface roughness in the first region different from a second surface roughness in the second region.