An organic electroluminescence device is provided which employs a metal
oxide electrode having particular composition distribution of elements to
extend the life. A conventional approach for extending the life of an
electroluminescence device is not provided by considering the degradation
mechanism of how the organic electroluminescence device is degraded by
the driving with electric current. The composite ratio of compounds of an
electrode made of metal oxide forming part of the organic
electroluminescence device is substantially uniform from a surface
through which the carriers are injected from the electrode toward a
deeper section in a bulk layer of the electrode. Thus, the electrode has
stoichiometrically stable composition to prevent the degradation of
electrode materials and diffusion into the organic layer, thereby
providing a longer life.