A biometric authentication device comprising: an acquisition unit configured to acquire time-series biological images including a vein pattern by repeatedly imaging a biological part of a person in a time period in which a relative position with respect to the biological part is changed; a detection unit configured to detect a plurality of focusing points in each of at least part of the time-series biological images, the plurality of focusing points being preset points on an image of the biological part which correspond among the time-series biological images; a calculation unit (34, 36, 37) configured to calculate for each of the plurality of focusing points a first time range which is a time period in which a degree of divergence between a first temporal variation and a second temporal variation is larger than a threshold value for evaluating if a focusing point of said each of the plurality of focusing points is affected by glare, the first temporal variation being a temporal variation of brightness with respect to pixels corresponding to said each of the plurality of focusing points detected from each of at least the part of the time-series biological images, the second temporal variation being a temporal variation of brightness with respect to pixels corresponding to a whole image of each of at least the part of the time-series biological images; a generation unit configured to generate a biological image by correcting a first pixel value corresponding to a focusing point of the plurality of focusing points within the first time range on the basis of a second pixel value corresponding to the focusing point outside the first time range; and an authentication unit configured to perform personal authentication of the person by using the biological image that is generated. an acquisition unit configured to acquire time-series biological images including a vein pattern by repeatedly imaging a biological part of a person in a time period in which a relative position with respect to the biological part is changed; a detection unit configured to detect a plurality of focusing points in each of at least part of the time-series biological images, the plurality of focusing points being preset points on an image of the biological part which correspond among the time-series biological images; a calculation unit (34, 36, 37) configured to calculate for each of the plurality of focusing points a first time range which is a time period in which a degree of divergence between a first temporal variation and a second temporal variation is larger than a threshold value for evaluating if a focusing point of said each of the plurality of focusing points is affected by glare, the first temporal variation being a temporal variation of brightness with respect to pixels corresponding to said each of the plurality of focusing points detected from each of at least the part of the time-series biological images, the second temporal variation being a temporal variation of brightness with respect to pixels corresponding to a whole image of each of at least the part of the time-series biological images; a generation unit configured to generate a biological image by correcting a first pixel value corresponding to a focusing point of the plurality of focusing points within the first time range on the basis of a second pixel value corresponding to the focusing point outside the first time range; and an authentication unit configured to perform personal authentication of the person by using the biological image that is generated.