A measurement system includes an illumination unit, imaging unit, acquisition unit and correction unit. A measurement target is irradiated with illumination light. The imaging unit captures an image of light reflected by or transmitted through the measurement target. The acquisition unit acquires positional relationship information representing a positional relationship between the illumination unit and the measurement target and between the imaging unit and the measurement target. The correction unit corrects a luminance of at least one of the illumination light emitted by the illumination unit and the captured image based on the positional relationship information in such a way as to correct a luminance change of the measurement target image, wherein at least two of the measurement target, the illumination unit, and the imaging unit are variable in spatial position.