An OLED device comprises a cathode, an electron-transporting layer (ETL), a light-emitting layer (LEL) containing a fluorescent light-emitting material, a hole-transporting layer (HTL), and an anode, in that order, wherein the ETL comprises a mixture of compounds, including a first compound and at least one second compound, and wherein there is present a hole blocking layer (HBL) adjacent to the LEL on the cathode side. It provides a reduced drive voltage with comparable color hue. The first compound is present in an amount of 50% to 90% by volume and is represented by Formula (2): ##STR00001## Wherein R.sub.1 and R.sub.4 represent the substituent and neither are hydrogen; R.sub.2 and R.sub.3 represent hydrogen; Ar.sup.1 and Ar.sup.4 represent the same aromatic group; and Ar.sup.2 and Ar.sup.3 represent the same aromatic group.