A biometric authentication apparatus 10 according to the present invention can be installed in facilities such as airports in order to improve the reliability of biometric authentication to ensure a high level of security. The biometric authentication apparatus 10 includes a illumination unit 11 which irradiates a human finger with light; an image acquisition unit 13 which acquires a plurality of images indicating changes in luminance by receiving light scattered at the human finger that is a part of the light with which the human finger is irradiated by the illumination unit 11 and converting the received light to luminance information according to the intensity of the light; an image-to-biometric-information conversion unit 14 which converts the plurality of images acquired by the image acquisition unit 13 to biometric information indicating a pulse wave in the human finger; and a biometric authentication unit 16 which performs biometric authentication when a pulse wave signal which is the biometric information resulting from the conversion by the image-to-biometric-information conversion unit 14 is greater than a predetermined threshold.