An OLED device comprising a cathode, an electron-transporting layer, a light-emitting layer containing a fluorescent light-emitting material, a hole-transporting layer, and an anode, in that order, wherein the ETL comprises a mixture of compounds, including a first compound and at least one second compound wherein the mixture of compounds includes: a) a first compound that has the lowest LUMO value of the compounds in the ETL layer, the amount being greater than or equal to 20% by volume and less than or equal to 90% by volume of the ETL layer, wherein the first compound is represented by Formula: wherein: R 1 and R 4 represent the same substituent which is an alkyl group or an aryl group; R 2 and R 3 represent hydrogen; Ar 1 and Ar 4 represent the same aromatic group; and Ar 2 and Ar 3 represent the same aromatic group; b) at least one second compound that is a low voltage electron transport material, exhibiting a higher LUMO value than the first compound, the total amount of said first compound and said second compound(s) being equal to 100% by volume of the ETL layer, wherein the second compound(s) is/are represented by Formula, wherein M is an alkali metal, an alkaline earth metal, aluminum, gallium, zinc, zirconium, or boron; n is an integer of from 1 to 4, and is equal to the oxidation state of the metal M; and each Z a and Z b independently represents the atoms necessary to complete an aromatic ring group; and wherein there is present a hole blocking layer adjacent to the LEL on the cathode side, wherein the hole-blocking layer includes a compound represented by Formula as defined above; Formula as shown below, or Formula as shown below: wherein: W 1 -W 8 represent hydrogen; and W 9 -W 10 independently represent substituents selected from the group consisting of: 1-naphthyl, 2-naphthyl, 4-biphenyl, and 3-biphenyl; wherein: m is an integer of from 3 to 8; Z is O, NR 29, or S; R 25, R 26, R 27, R 28, and R 29 represent hydrogen, an alkyl group, or an aryl group; and Y is a linkage unit comprising an alkyl group or an aryl group that connects the multiple heterocycles together. a) a first compound that has the lowest LUMO value of the compounds in the ETL layer, the amount being greater than or equal to 20% by volume and less than or equal to 90% by volume of the ETL layer, wherein the first compound is represented by Formula: wherein: R 1 and R 4 represent the same substituent which is an alkyl group or an aryl group; R 2 and R 3 represent hydrogen; Ar 1 and Ar 4 represent the same aromatic group; and Ar 2 and Ar 3 represent the same aromatic group; R 1 and R 4 represent the same substituent which is an alkyl group or an aryl group; R 2 and R 3 represent hydrogen; Ar 1 and Ar 4 represent the same aromatic group; and Ar 2 and Ar 3 represent the same aromatic group; b) at least one second compound that is a low voltage electron transport material, exhibiting a higher LUMO value than the first compound, the total amount of said first compound and said second compound(s) being equal to 100% by volume of the ETL layer, wherein the second compound(s) is/are represented by Formula, wherein M is an alkali metal, an alkaline earth metal, aluminum, gallium, zinc, zirconium, or boron; n is an integer of from 1 to 4, and is equal to the oxidation state of the metal M; and each Z a and Z b independently represents the atoms necessary to complete an aromatic ring group; and wherein there is present a hole blocking layer adjacent to the LEL on the cathode side, wherein the hole-blocking layer includes a compound represented by Formula as defined above; Formula as shown below, or Formula as shown below: wherein: W 1 -W 8 represent hydrogen; and W 9 -W 10 independently represent substituents selected from the group consisting of: 1-naphthyl, 2-naphthyl, 4-biphenyl, and 3-biphenyl; wherein: m is an integer of from 3 to 8; Z is O, NR 29, or S; R 25, R 26, R 27, R 28, and R 29 represent hydrogen, an alkyl group, or an aryl group; and Y is a linkage unit comprising an alkyl group or an aryl group that connects the multiple heterocycles together. W 1 -W 8 represent hydrogen; and W 9 -W 10 independently represent substituents selected from the group consisting of: 1-naphthyl, 2-naphthyl, 4-biphenyl, and 3-biphenyl; m is an integer of from 3 to 8; Z is O, NR 29, or S; R 25, R 26, R 27, R 28, and R 29 represent hydrogen, an alkyl group, or an aryl group; and Y is a linkage unit comprising an alkyl group or an aryl group that connects the multiple heterocycles together.