An image reading apparatus includes a scanner structured to reads an image formed on a medium which is conveyed; a calibration member located opposite to the scanner and structured to reflect irradiation light to be radiated to the medium when reading an image; a first roller arranged in a fixed position and structured to guide a conveying direction of the medium passing between the scanner and the calibration member; and a second roller arranged in a variable position in accordance with the stiffness of the medium and structured to guide the conveying direction of the medium passing between the scanner and the calibration member.