An optical image measuring apparatus capable of effectively obtaining a direct current component of a heterodyne signal which is composed of background light of interference light is provided. The optical image measuring apparatus includes: an optical interference system in which a light beam from a light source is divided into signal light and reference light by a beam splitter, a frequency of the reference light is shifted by a frequency shifter, and the signal light propagating through an object to be measured and the reference light reflected on a mirror are superimposed on each other by the beam splitter to produce interference light; beam splitters for dividing the interference light into interference light beams; shutters serving as an intensity modulating unit for modulating intensities of the respective interference light beams at predetermined intervals; CCDs for receiving the respective interference light beams whose intensities are modulated and outputting electrical signals; and a signal processing portion serving as a calculating unit for calculating an intensity of the direct current component corresponding to the background light of the interference light based on the outputted electrical signals.