An organic EL display device having comprises a supporting substrate; and an organic EL element including an organic luminescent medium sandwiched between a lower electrode and an upper electrode thereon. A color changing medium and/or a transparent resin layer are arranged between the supporting substrate and the lower electrode. EL emission is taken out from the lower electrode. Various relationships are indicated among the refractive indices of the various elements of the organic EL display device. In such arrangement, a large quantity of EL emission can be taken to the outside.