An image determination device according to the present invention includes: an extraction means for extracting a figuration pattern of an identification subject in a finger reflected on an image a detection means for detecting a joint line in the finger and a determination means for determining the image as an image to be registered or an image to be collated with a registration subject when a joint line exists in a first range which is set in one of respective regions obtained when separating the image with the center line that corresponds to a direction perpendicular to the longitudinal direction of the finger and that is set as the border, and a blood vessel amount which is equal to or more than a predetermined threshold value exists in a second range which is set in the other region different from the region in which the first range is set.
