A dense cathode electrode layer having a step coverage is to be formed on an electron injection layer. The electron injection layer in which fine particles of an electron injection material is dispersed in an organic thin film having an electron transport property is formed by vapor co-depositing the electron transport material and the electron injection material; and a cathode electrode layer made of an alloy layer of MgAg is formed by a sputtering method. Since lower portions of the fine particles of the electron injection material dispersed in the surface of the organic thin film are buried in the organic thin film, the electron injection particles are not peeled off even if sputtering particles collide with the electron injection particles, and the upper portions are in contact with the cathode electrode layer formed by sputtering particles.