A light emitting device includes a substrate; a first electrode disposed on the substrate; an organic material layer disposed on the first electrode and including a first resonance auxiliary layer; and a second electrode disposed on the organic material layer, wherein the first resonance auxiliary layer includes a first compound with a lowest unoccupied molecular orbital (LUMO) level of −4 eV or less and a second compound with a highest occupied molecular orbital (HOMO) level of −4 eV or less, and wherein the first resonance auxiliary layer has a thickness of 20% to 90% of a total thickness of the organic material layer.