An OCT measurement apparatus includes a level detection section which detects the signal level of a piece of signal intensity information in interference information outputted from an interference beam detection section, a variable optical attenuator (VOA) which adjusts the light quantity of a return beam of a reference beam, and a light quantity control section which controls the VOA on the basis of the signal level of the piece of signal intensity information in the interference information detected by the level detection section. Accordingly, an interference signal at an appropriate level can be detected without saturation of the interference signal and reduction of an S/N ratio, and optical structure information of an object to be measured can be generated using the interference signal.
