The light-emitting element emits light itself. The element includes a light-emitting portion having a higher refractive index than a refractive index of air and a diffraction grating structure provided to a light-emitting side surface of the light-emitting portion. The function that a minimum light-emission value is equal to or less than 50% of a maximum light-emission value when white light is emitted from the light-emitting portion is realized. The function is obtained by further including a color-separation filter provided between the light-emitting portion and the light-emitting side surface and making a minimum value of a spectral product obtained from a light-emission waveform of the white light emitted from the light-emitting portion and a spectral transmittance of said color-separation filter equal to or less than 50% of a maximum value thereof, or by adjusting a light-emission ratio of the light-emitting materials for said at least two primary colors among the light-emitting materials for the three primary colors.