An electron transport layer includes an electron transport material (host material) and a carrier transportable dopant. The carrier transportable dopant is contained 1% by weight to 50% by weight, preferably 1% by weight to 10% by weight for the electron transport material. A compound having a carbazole group or a derivative of the compound is employed as the carrier transportable dopant. A complex of an 8-hydroxyquinoline derivative and metal is employed as the electron transport material.