A light-emitting device and a panel display device are provided. The light-emitting device includes: first electrodes positioned on a first sub-pixel, a second sub-pixel, and a third sub-pixel, respectively; a second electrode facing first electrodes; a first emission layer on the first sub-pixel to emit a first color light; a second emission layer on the second sub-pixel to emit a second color light; a first layer integrated with the first sub-pixel, the second sub-pixel, and the third sub-pixel; a first auxiliary layer between the first layer and the first emission layer; and a first interlayer between the first auxiliary layer and the first emission layer. The absolute value of the highest occupied molecular orbital (HOMO) energy level of the first interlayer is greater than the absolute value of the HOMO energy level of the first auxiliary layer, and is smaller than the absolute value of the HOMO energy level of the first emission layer. The absolute value of the lowest unoccupiedmolecular orbital (LUMO) energy level of the first interlayer is greater than that of a LUMO energy level of the first auxiliary layer, and is smaller than the absolute value of the LUMO energy levelof the first emission layer.