Disclosed is an organic electroluminescent display device. The present invention includes a transparent substrate, an anode formed on the transparent substrate, an organic layer stacked on the anode, a cathode formed on the organic layer, and a buffer layer formed between the cathode and organic layer, the buffer layer including a first material selected from the group consisting of an alkaline metal and an alkaline earth metal compound and a second material selected from the group consisting of an organic compound and an organic metal compound.