An optical interferometric measurement apparatus includes an interference optical system (2, 3) to output a monitoring interference signal S(t) and a measurement interference signal S(t) in accordance with light emitted from a wavelength-swept light source (1), and a controller (4) to measure a movement of an object to be measured (3k). The controller (4) has a storage (4b, 4b') to store monitoring data acquired by sampling the monitoring interference signal S(t) in each period T of the light source (1) and measurement data acquired by sampling the measurement interference signal S(t) in each period T of the light source (1) and Fourier transformation unit (4d) to apply Fourier transform to the measurement data. The controller (4) determines a phase Õ of the measurement interference signal S(t) based on the Fourier-transformed measurement data and measures the movement of the object (3k) based on the phase.
