A dynamic light scattering measurement device (1) includes an irradiation section that applies light emitted from a low-coherence light source (10) to a sample (40) that includes particles (42), a spectral intensity acquisition section (62) that disperses reflected light from a reference plane and scattered light from the sample (40) that has passed through the reference plane to acquire a spectral intensity of interference light of the reflected light and the scattered light, the reference plane being situated to intersect an optical path through which the light is applied to the sample, and a measurement section (80) that measures dynamic light scattering of the sample (40) based on the acquired spectral intensity.