An emitter has a plurality of types of light-emitting units with different changes in emission characteristics over time. In addition, the emitter includes a deterioration adjustment device which adjusts the deterioration of the emission characteristics over time in a predetermined type of light-emitting unit. The light-emitting units respectively include a light-emitting layer and a hole donor which supplies positive holes to the light-emitting layer, and the deterioration adjustment device may be the hole donor in which the thickness is adjusted based on the deterioration in emission characteristics over time in the predetermined type of light-emitting unit.