PURPOSE: To provide a superior imaging device capable of surely processing an image in a short time without executing the correction processing required by variation of illuminance on a surface to be measured.

CONSTITUTION: Illuminance 5, 6 are placed on symmetric positions with respect to an object 2 to be measured and emit light on a surface of the object 2 such that illuminance is uniform in the whole surface. An image of the surface of the object 2 is imaged by a CCD camera to give a uniform illumination to the entire surface of the object 2. Thereby, it is possible to surely take the image of the surface of the object 2 in a short time without executing the correction processing for variation of illuminance.