An optical measurement apparatus is provided with: a light source configured to irradiate a measurement target in which fluid flows, with light； a light receiver configured to receive scattered light of irradiated light from the measurement target and configured to output a light receiving signal corresponding to intensity of the scattered light； a disturbance generator configured to generate a disturbance signal for fluctuating a drive current, which is supplied to said light source； and an adjuster configured to adjust the drive current on the basis of a result of a comparison between a signal generated on the basis of the light receiving signal and the disturbance signal.
