Abstract: An optical measuring device which measures absorbance of a measuring object at a plurality of wavelengths, the optical measuring device comprising: a light source device; and an optical measuring part which irradiates the measuring object with light from the light source device and performs optical measurement of the measuring object based on light from the measuring object, wherein the light source device has a first light source, a second light source, and a light source control part which drives the first light source and the second light source, the light source control part performs heating and light emitting drive of the first light source, and drives the second light source, and the light source device irradiates the measuring object with combined light of light from the first light source and light diffused and reflected on a surface of the filament.