A light source unit includes: elemental light sources each including light emitting elements and drive circuits; an integrated control circuit that controls the drive circuits; and band optical characteristic acquisition sections that receive light of an amount correlated with a total light amount of output luminous fluxes to acquire light emitting intensity indicating values and wavelength deviation indicating values. The integrated control circuit at least intermittently acquires band optical characteristic acquisition data to generate the light emitting intensity indicating values and the wavelength deviation indicating values. The integrated control circuit holds light emitting intensity indicating value target variation information, and determines the variation of the light emitting intensity indicating values, in accordance with the light emitting intensity indicating value target variation information belonging to one appearance mode of the wavelength deviation indicating values assumed on a basis of an actual mode of the generated wavelength deviation indicating values.