A paper medium recognition device according to one embodiment of the present invention includes: a main body that provides a transportation path in which an alignment reference line for aligning a paper medium is arranged on one side; and an alignment unit which has a transportation roller which transports the paper medium in the longitudinal direction along the transportation path, and which has an alignment roller that is arranged in the direction orthogonal to the transportation roller so as to transport the paper medium in the width direction toward the alignment reference line. A phase difference is provided during the rotation of the transportation roller and the alignment roller, and thus the paper medium can be alternately transported in the longitudinal direction and width direction.