A light source device includes: a semiconductor light-emitting element that emits, according to an input value, light having first wavelength; a wavelength converting element that converts, with a nonlinear optical effect, the light having the first wavelength emitted by the semiconductor light-emitting element into light having second wavelength; a light-amount measuring unit that measures a light amount of the light having the second wavelength emitted from the wavelength converting element; an equivalent-light-amount calculating unit that calculates, on the basis of the measured light amount measured by the light-amount measuring unit, an equivalent light amount equivalent to a light amount of the light having the first wavelength; and a light-amount correcting unit that corrects an emitted light amount of the semiconductor light-emitting element using the input value and the equivalent light amount.