The present invention provides a light-emitting device which can be driven at a low voltage and has high luminance, high efficiency, and has a long lifetime even as an organic EL device using phosphorescence. The light-emitting device of the present invention is a light-emitting device including an anode, a cathode, and an organic light-emitting layer sandwiched between the anode and the cathode, in which the organic light-emitting layer is composed of a host material and one or more kinds of dopants, a difference in electron affinity between the host material and at least one kind of the dopants is 0.3 eV or less, and a difference in ionization potential between the host material and the at least one kind of the dopants is 0.8 eV or less.