An image reading apparatus, which reads an image on an original, including: a light source extending along a main scanning direction to illuminate the original; a plurality of line sensors configured to receive light reflected from the original and to output light intensity signals; a storage unit configured to store reference data; and a determination unit configured to obtain determination data regarding hue based on a light intensity signal output from one of the plurality of line sensors that receive light reflected from a reflective reference member illuminated by the light source and a light intensity signal output from another of the plurality of line sensors that receive light reflected from the reflective reference member illuminated by the light source and to determine a hue balance of the light source based on the determination data and the reference data stored in the storage unit.