In order to correct chromatic aberration accurately and read out a document original properly, an image reader apparatus includes a chromatic aberration correction chart, a CCD linear sensor, and a correction processing unit. A chromatic aberration correction chart includes a high reflectance portion and a low reflectance portion lower than the high reflectance portion. A CCD linear sensor receives light reflected from the chromatic aberration correction chart. A correction processing unit corrects chromatic aberration of image data according to a light receiving position in the photoelectric conversion unit receiving light of a first wavelength included in the reflected light from the chromatic aberration correction chart and a light receiving position in the photoelectric conversion unit receiving light of a second wavelength included in the reflected light from the chromatic aberration correction chart.