Abstract: To provide a paper sheet discriminating apparatus and method capable of discriminating even a paper sheet such as a US dollar bill, in which the location of a pattern is dislocated from the periphery due to a printing shear or a cutting dislocation, efficiently without any drop of the discrimination percentage by using the image of the paper sheet. A paper sheet discriminating apparatus for deciding at least the kind of a paper sheet on the basis of its pattern by sampling the image of its whole surface. The dislocation of the pattern, as viewed from the contour, is detected on the basis of the marginal length of the paper sheet from the outer periphery to the pattern, thereby to correct a pixel position for providing a base point for the image recognition of the paper sheet, with the detected dislocation.