An organic light emitting apparatus comprising a substrate and a plurality of organic light emitting devices having different emission colors to each other formed on the substrate, each of the plurality of organic light emitting devices including a cathode, an electron injection layer which is in contact with the cathode, organic compound layers including a light emitting layer, and an optically-transparent anode, the electron injection layer including an organic compound and at least one of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound. The electron injection layer has a thickness adjusted for each of the different emission colors so that each of the plurality of organic light emitting devices having the different emission colors enhances light emitted from the light emitting layer.