A light source unit includes an excitation light source, a plurality of light sources at least one of which emits a light ray in a wavelength band different from that of the excitation light source, a plurality of collimator lenses which make light rays from the light sources into parallel ones, a luminous light emitting device which receives the light ray from the excitation light source to emit a luminous light ray, a microlens array which diffuses the light rays from the light sources to a predetermined range and distributes the luminance thereof uniformly within the predetermined range and a collective lens which collects the light rays from the light sources which are emitted from the microlens array, and the light sources are disposed so that the light rays from the plurality of light sources intersect the light ray from the excitation light source at right angles.