This biometric authentication device has: a recording unit that records a first indicator, which represents a first position, and first form data, representing the form of biometric information of a hand of a registered user when a finger of the hand is in the state of being in the first position, and a second indicator, which indicates a second position, and second form data representing the form of biometric information of the hand when a finger of the hand is in the state of being in the second position; a position identification unit that calculates a third indicator, which represents a third position of a finger of the hand of the user depicted in a biometric image; a biometric information extraction unit that generates third form data representing the form of the biometric information of the hand of the user depicted in the biometric image; a correction unit that determines form data resulting from correcting the first or second form data in a manner so as to eliminate the differences in the form of biometric information resulting from differences between the third position and the first position or second position in accordance with the ratio of the difference between the third indicator and the first indicator or second indicator to the difference between the first and second indicator; and a comparison unit that compares the third form data and the corrected form data.