The image reading apparatus including a reading unit configured read an image of a document according to a read request transmitted from an external device, includes a detection unit configured to detect a state of the document to be read by the reading unit, a reception unit configured to receive a request from the external device to obtain a state of the image reading apparatus, a power supply unit configured to, in a power saving state where power supply to the reading unit and the detection unit is stopped, supply power to the detection unit based on the reception of the request, and a transmission unit configured to transmit the state of the document to be read by the reading unit detected by the detection unit to which the power is supplied by the power supply unit, to the external device as a response to the request.