A light source unit comprising a light source for emitting excitation light and a luminescent material for emitting luminescent light by excitation light emitted from the light source, the light source unit comprising: a light emitting plate which has a plurality of segment areas on a base material and in which at least one of the plurality of segment areas is made into a reflecting portion, a luminescent material layer is formed on the reflecting area which emits light of a predetermined wavelength band by receiving excitation light, and at least one of the plurality of segment areas is made into a transmission portion which transmits light; a primary light source which shines excitation light on to the luminescent material layer and the transmission portion of the light emitting plate; characterised by a secondary light source which emits light of a wavelength band which is different from luminescent light emitted from the luminescent material layer and excitation light emitted from the primary light source; a collective optical system which collects light emitted from the light emitting plate and light emitted from the secondary light source so as to cause them to converge to the same optical path, the collective optical system comprising: a dichroic mirror (151 a) which is disposed between the primary light source and the light emitting plate to allow the passage of excitation light and to reflect luminescent light from the luminescent material; and pluralities of reflecting mirrors and dichroic mirrors which collect excitation light that passes through the transmission portion of the light emitting plate, luminescent light reflected on the dichroic mirror and light emitted from the secondary light source so as to cause them to converge to the same optical path to be emitted towards the same direction; and light source control means which controls the emission of light from the primary light source and the secondary light source. a light emitting plate which has a plurality of segment areas on a base material and in which at least one of the plurality of segment areas is made into a reflecting portion, a luminescent material layer is formed on the reflecting area which emits light of a predetermined wavelength band by receiving excitation light, and at least one of the plurality of segment areas is made into a transmission portion which transmits light; a primary light source which shines excitation light on to the luminescent material layer and the transmission portion of the light emitting plate; characterised by a secondary light source which emits light of a wavelength band which is different from luminescent light emitted from the luminescent material layer and excitation light emitted from the primary light source; a collective optical system which collects light emitted from the light emitting plate and light emitted from the secondary light source so as to cause them to converge to the same optical path, the collective optical system comprising: a dichroic mirror (151 a) which is disposed between the primary light source and the light emitting plate to allow the passage of excitation light and to reflect luminescent light from the luminescent material; and pluralities of reflecting mirrors and dichroic mirrors which collect excitation light that passes through the transmission portion of the light emitting plate, luminescent light reflected on the dichroic mirror and light emitted from the secondary light source so as to cause them to converge to the same optical path to be emitted towards the same direction; and a dichroic mirror (151 a) which is disposed between the primary light source and the light emitting plate to allow the passage of excitation light and to reflect luminescent light from the luminescent material; and pluralities of reflecting mirrors and dichroic mirrors which collect excitation light that passes through the transmission portion of the light emitting plate, luminescent light reflected on the dichroic mirror and light emitted from the secondary light source so as to cause them to converge to the same optical path to be emitted towards the same direction; and light source control means which controls the emission of light from the primary light source and the secondary light source.