Disclosed is an organic light emitting display device including: a first substrate including a plurality of pixel regions; a thin film transistor (TFT) formed in each of the plurality of pixel regions of a display unit of the substrate; a first electrode formed in the pixel region of the display unit; an organic light emitting unit formed in the pixel region of the display unit to emit light; a second electrode formed on the organic light emitting unit of the display unit; a passivation layer formed on the second electrode; and a second substrate formed on the passivation layer, wherein the second electrode is made of an alloy of silver (Ag) and an alkaline earth metal or an alloy of silver (Ag) and a rare earth metal, a composition ratio of the silver (Ag) and the alkaline earth metal or the rare earth metal is (more than 1):1, and a thickness of the second electrode ranges from 200 Å to 350-400 Å.