An image reading apparatus including: a feeding device; a first reading unit that scans an image of a first surface of the document fed by the feeding device; a second reading unit that scans an image of a second surface of the document fed by the feeding device, wherein the second surface is opposite to the first surface; a first processing unit that processes the image data read by the first reading unit when performing a double-sided reading; a second processing unit that processes the image data read by the second reading unit when performing the double-sided reading, and a control unit that, when a one-sided reading of a following document is performed while one of the processing units is performing a processing of a one-sided reading of a preceding document, controls the other processing unit to perform processing of the one-sided reading of the following document.