An organic light emitting display device and a manufacturing method of forming an inorganic layer formed on the top of the sealing film with nitride are disclosed. In one embodiment, the organic light emitting display device includes: i) a substrate on which at least one organic light emitting diode is formed and ii) a sealing film stacked with at least one organic film and inorganic film and sealing the organic light emitting diode, wherein the top of the sealing film is formed of an inorganic film formed of nitride.