An organic light emitting display device having a display substrate; a display element layer formed on the display substrate and including a plurality of pixels, a thin film encapsulation layer which covers and protects the display substrate and the display element layer; a function film disposed on the thin film encapsulation layer, a first adhesive layer disposed between the thin film encapsulation layer and the functional film, a window attached onto the functional film which protects the display element layer, and a second adhesive layer disposed between the functional film and the window, in which the first adhesive layer and the second adhesive are formed by deposition, a surface processing is performed, and facing surfaces are adhered with each other.