An image scanning apparatus includes a transport roller transporting an original, a CCD scanning a first side of the original, a CIS scanning unit scanning a second side of the original, and a flap for reversing the original and sending the original to a transport path. A CPU controls the transport roller, the CCD and the CIS scanning unit to scan each side of the original. The CPU determines from the result of scanning whether or not each side of the original includes a predetermined pattern. When the CPU cannot identify from the result of scanning of the second side whether or not the second side includes a predetermined pattern, the CPU controls the flap and a transport unit to reverse the original and cause the CCD to scan the second side.