Rectangular partial areas “Ri” for use in template matching in a process of determining match/mismatch between fingerprint images are spread adjacently to each other in one of the images. A boundary-including partial area is set in a portion including a crossing point of cross-shaped boundaries defined by the four neighboring partial areas. The plurality of partial areas formed of the neighboring partial areas and the boundary-including partial area are used as a template so that the number of the partial areas can be increased while ensuring a certain size of the partial area. Further, the boundary-including partial area covers the boundary between the neighboring partial areas so that continuity of image data at the boundary between the neighboring partial areas can be reflected in the determination of the match/mismatch between the images.