According to one embodiment, an image reading apparatus includes an illumination unit (21) to irradiate a surface of a sheet (1) with light from an oblique direction at a predetermined angle of incidence (α), a reading unit (24) to receive light reflected from a reading range on the sheet (1) and to acquire a sheet image, and a reflecting mirror (22, 25) that is disposed in a direction of an angle of emission (α) that is equal to the angle of incidence (α), that has a specular surface that is parallel to the reading range (D), and that reflects light reflected from the sheet (1) toward the reading range (D) with the specular surface.