An image reading apparatus 300 comprises: the scanner device SD which reads information about a sheet P conveyed on a paper conveying route PP and information about a position, a form and a color of an image formed on the sheet P; a spectrophotometer CI which reads information about a color of an image formed on a sheet P conveyed on the paper conveying route PP; and a support base TR which incorporates the paper conveying route and a motor for conveying a sheet and can be pulled out from a main body together with the paper conveying route and the motor. The scanner device SD is not mounted on the support base TR but fixed to the main body of the image reading apparatus. The spectrophotometer CI is mounted on and fixed to the support base TR, and spaced from the paper transfer route PP by a predetermined distance.