A light emitting device having a relatively simple configuration is provided that emits stable light having a plurality of wavelengths. The light emitting device 1 comprises, in sequence, a composite substrate 3 and a gallium nitride-based semiconductor layer 5 including a light emitting layer 9. The composite substrate 3 includes a base 19 and a gallium nitride layer, the gallium nitride-based semiconductor layer 5 being disposed on a principal surface of the gallium nitride layer, the angle θ defined by the c-axis of the gallium nitride layer and a normal line N1 to the principal surface S1 of the gallium nitride layer ranging from 50 to 130 degrees, the light emitting layer 9 emitting light with an absolute value of the degree of polarization of 0.2 or more, the base 19 containing a fluorescent material that emits a fluorescent light component induced by irradiation of a light component emitted from the light emitting layer 9. Accordingly, the light emitting device 1 can emit white light produced by superposition of blue light directly emitted from the light emitting layer 9 and yellow light induced by blue light incident on the base 19 from the light emitting layer 9.