A flexible display device includes: a display substrate which is divided into a first region corresponding to a within-cell region of an integrated devices sheet from which the flexible display device is cut and into a second region corresponding to an outside-the-cell region of the integrated devices sheet, where within the first region there is provided a display unit including a light emitting element layer; a patterned inorganic film layer formed to be substantially continuously present within the first region of the display substrate and to be not present or not substantially continuously present within the second region of the display substrate; and a thin film encapsulation layer formed on the inorganic film layer to encapsulate the substantially continuously present portion of the inorganic film layer that is within the first region and the display unit, wherein an outer boundary of the thin film encapsulation layer is located more inwardly and toward an outer boundary of the display unit than is an outer boundary of the substantially continuously present portion of the inorganic film layer.