The present invention provides an electro-optical device capable of achieving an increased light emission efficiency and an enhanced visibility. An organic electroluminescents (EL) display device has a plurality of material layers including a luminescent layer. In a plurality of material layers layered in the direction of light emission from the luminescent layer, first and second insulating interlayers are disposed between a substrate, which is positioned at the outermost surface, and the luminescent layer. The first and second insulating interlayers have a refractive index lower than that of the substrate. Accordingly, by forming predetermined materials having a low refractive index, the resulting low refractive index layers have a low dielectric constant, and consequently, the capacity between wires can be reduced.