The object is to determine an area from which biometric data is acquired, from among a plurality of parts of a living body in a simple manner. In a part determining unit (3), a first particular region (8a) and a second particular region (8b) are preset at portions of an image capturing area (7) for a living body (9), and a finger web is preset as a feature part of the living body. The first particular region (8a) and the second particular region (8b) are rectangular regions and are positioned at two opposing peripheral portions (an upper peripheral portion and a lower peripheral portion, respectively) of the image capturing area (7), which is rectangular as well. When a hand is placed over the image capturing area (7) for the purpose of acquiring biometric data from the palm, a part near the wrist is positioned in the first particular region (8a), and a part near the base of the four fingers except the thumb is positioned in the second particular region (8b). The part determining unit (3) determines the part of the living body positioned in the image capturing area (7) on the basis of feature parts in image data (5) corresponding to the first particular region (8a) and image data (6) corresponding to the second particular region (8b).
