A biometric information processing device comprising: a fingerprint information obtaining unit which has a fingerprint sensor with a region on which multiple fingers are to be placed, and is directed for obtaining fingerprint information input from the fingerprint sensor; a vein information obtaining unit which has a vein sensor with a region on which a palm is to be placed, the vein sensor being set adjacent to the fingerprint sensor, and is directed for obtaining vein information input from the vein sensor; a fingerprint information input determining unit that obtains fingerprint position information indicating fingerprint positions on the fingerprint sensor from fingerprint information obtained by the fingerprint information obtaining unit, and determining how fingers are placed on the fingerprint sensor based on the fingerprint position information and a predetermined fingerprint reference information; a vein information input determining unit that obtains palm position information indicating a palm position on the vein sensor from vein information obtained by the vein information obtaining unit, and determining how a palm is placed on the vein sensor based on the palm position information and a predetermined palm reference information; a mutual feedback information determining unit that determines position correcting information on one of or both the fingerprint position and the palm position based on how fingers are placed on the fingerprint sensor determined by the fingerprint information input determining unit and how a palm is placed on the vein sensor determined by the vein information input determining unit; a notifying unit that notifies position correcting information obtained by the mutual feedback information determining unit. a fingerprint information obtaining unit which has a fingerprint sensor with a region on which multiple fingers are to be placed, and is directed for obtaining fingerprint information input from the fingerprint sensor; a vein information obtaining unit which has a vein sensor with a region on which a palm is to be placed, the vein sensor being set adjacent to the fingerprint sensor, and is directed for obtaining vein information input from the vein sensor; a fingerprint information input determining unit that obtains fingerprint position information indicating fingerprint positions on the fingerprint sensor from fingerprint information obtained by the fingerprint information obtaining unit, and determining how fingers are placed on the fingerprint sensor based on the fingerprint position information and a predetermined fingerprint reference information; a vein information input determining unit that obtains palm position information indicating a palm position on the vein sensor from vein information obtained by the vein information obtaining unit, and determining how a palm is placed on the vein sensor based on the palm position information and a predetermined palm reference information; a mutual feedback information determining unit that determines position correcting information on one of or both the fingerprint position and the palm position based on how fingers are placed on the fingerprint sensor determined by the fingerprint information input determining unit and how a palm is placed on the vein sensor determined by the vein information input determining unit; a notifying unit that notifies position correcting information obtained by the mutual feedback information determining unit.