The invention provides an image reading apparatus which irradiates an object with light and reads an image on or of the object. The image reading apparatus includes a table on which the object is placed, a planar light source configured to emit light to the object, a range-finding section configured to measure a distance between the table and the object, and a control section configured to cause the planar light source to entirely or partially emit light. The control section controls a light emitting portion of the planar light source thereby to control a light collection spot for the planar light source to a position based on a measurement value obtained by the range-finding section.