PROBLEM TO BE SOLVED: To provide a technology which can perform highly accurate authentication by obtaining information on a plurality of biological tissues overlapping one another in a living body.SOLUTION: A biometric authentication device includes: a placement area on which a finger is placed at least one light source 3 for irradiating the finger with light imaging device 9 for imaging the light from the light source 3 to obtain at least one image an authentication processing part 10 for processing the image and a storage device 14 for storing registration information on at least one of a plurality of biological characteristics overlapping one another in the finger. The authentication processing part 10 obtains information on the distribution of pigment concentration related to a plurality of biological characteristics overlapping one another in a finger 1 from an image of the finger, obtains inputted information on at least one biological characteristic from the information on the distribution of pigment concentration, and uses the inputted information and the registration information and calculates a degree of the similarity to perform authentication based on the degree of the similarity.SELECTED DRAWING: Figure 1A
