An optical image measurement device comprises: a light amount adjustment part that adjusts the light amount of a laser beam generated by a low coherence light source 201; and a photodiode 105 placed outside the light path of the laser beam irradiated on an eye E and capable of measuring the light amount, wherein the laser beam is input to the photodiode 105 by changing the direction of a galvanomirror 170B; the photodiode 105 measures the light amount of the input laser beam; and the light amount adjustment part previously stores a specified range of light amount and adjust the light amount of the laser beam generated by the low coherence light source 201 such that the light amount measured by the photodiode 105 falls within the specified range.