The measurement apparatus combines first and second lights from first and second light generators to focus the combined light to a sample, and detect the first or second light intensity-modulated by stimulated Raman scattering. The first light generator includes a light dispersion element separating the light from a light introducing optical system in different directions according to light frequencies, and drives at least one of the light dispersion element and part of the light introducing optical system so as to change an incident angle of the light to the light dispersion element to extract part of the separated light, thereby making a light frequency of the first light variable. The second light generator produces a plurality of the second lights having mutually different light frequencies. The apparatus measures a Raman spectrum by changing the light frequency of the first light.