A light emitting device comprising: a light emitting layer (111, 311) between an anode (102, 302) and a cathode (104, 304), and a first layer (121, 321) and a second layer (122, 322) included in the light emitting layer (111, 311), wherein the first layer (121, 321) includes a first organic compound and an organic compound having a hole transporting property, wherein the second layer (122, 322) includes a second organic compound and an organic compound having an electron transporting property, wherein the first layer (121, 321) is formed in contact with the second layer (122, 322) and is located between the second layer (122, 322) and the anode (102, 302), wherein the highest occupied molecular orbital levels and lowest unoccupied molecular orbital level of the organic compound having the hole transporting property and the organic compound having the electron transporting property are chosen such that holes are injected from the first layer (121, 321) into the second layer (122, 322) and electrons are injected from the second layer (122, 322) to the first layer (121, 321); wherein a difference between a highest occupied molecular orbital level of the organic compound having the hole transporting property and a highest occupied molecular orbital level of the organic compound having the electron transporting property is 0.3 eV or less, wherein a difference between a lowest unoccupied molecular orbital level of the organic compound having the hole transporting property and a lowest unoccupied molecular orbital level of the organic compound having the electron transporting property is 0.3 eV or less, wherein the organic compound having the electron transporting property is a high molecular compound selected from the group consisting of poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridin-3,5-diyl)], PF-Py, and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridin-6,6'-diyl)], PF-BPy, and the organic compound having the hole transporting property is a low molecular compound, and wherein the first organic compound and the second organic compound are the same compound. a light emitting layer (111, 311) between an anode (102, 302) and a cathode (104, 304), and a first layer (121, 321) and a second layer (122, 322) included in the light emitting layer (111, 311), wherein the first layer (121, 321) includes a first organic compound and an organic compound having a hole transporting property, wherein the second layer (122, 322) includes a second organic compound and an organic compound having an electron transporting property, wherein the first layer (121, 321) is formed in contact with the second layer (122, 322) and is located between the second layer (122, 322) and the anode (102, 302), wherein the highest occupied molecular orbital levels and lowest unoccupied molecular orbital level of the organic compound having the hole transporting property and the organic compound having the electron transporting property are chosen such that holes are injected from the first layer (121, 321) into the second layer (122, 322) and electrons are injected from the second layer (122, 322) to the first layer (121, 321); wherein a difference between a highest occupied molecular orbital level of the organic compound having the hole transporting property and a highest occupied molecular orbital level of the organic compound having the electron transporting property is 0.3 eV or less, wherein a difference between a lowest unoccupied molecular orbital level of the organic compound having the hole transporting property and a lowest unoccupied molecular orbital level of the organic compound having the electron transporting property is 0.3 eV or less, wherein the organic compound having the electron transporting property is a high molecular compound selected from the group consisting of poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridin-3,5-diyl)], PF-Py, and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridin-6,6'-diyl)], PF-BPy, and the organic compound having the hole transporting property is a low molecular compound, and wherein the first organic compound and the second organic compound are the same compound.