An organic electroluminescent device having high efficiency, a long life time, and low cost, includes a substrate, a hole injecting electrode and an electron injecting electrode formed on the substrate, an organic material-containing organic layer between the electrodes, and an inorganic insulative electron injecting and transporting layer between the light emitting layer and the electron injecting electrode. The organic layer includes a light emitting layer containing a conjugated polymer, and the inorganic insulative electron injecting and transporting layer comprises three components. The first component is at least one oxide selected from the group consisting of lithium oxide, rubidium oxide, potassium oxide, sodium oxide, and cesium oxide. The second component is at least one of strontium oxide, magnesium oxide, and calcium oxide. The third component consists of silicon oxide, germanium oxide, or mixtures thereof.