An organic electro-luminescent display device according to an embodiment of the present invention includes a thin film transistor substrate including a base member; an organic material layer disposed on the base member in a display area and held between a lower electrode and an upper electrode; a dam formed on the base member in an external area surrounding the display area; and a sealing layer formed on the organic material layer, the sealing layer covering the display area, the sealing layer including a sealing planarization film formed of organic material and formed in an area surrounded by the dam, the sealing layer further including a sealing film formed of inorganic material and covering the dam. The dam includes moisture detection member.