A biometric authentication apparatus (20-2, 20-4) comprising a light source configured to irradiate light on a biometric target, and an imaging apparatus (1A, 1B)configured to capture an image including the biometric target, characterized in that there are provided: a storage unit configured to store a correction coefficient for each of a plurality of positions on a reference object, with respect to each distance from the light source to the reference object; a luminance computing unit configured to compute a luminance at each of a plurality of positions on the biometric target within the captured image; a distance measuring unit configured to measure a distance from the light source to the biometric target; and a process unit configured to correct the luminance at each of the plurality of positions on the biometric target within the captured image, based on the correction coefficient at each of the plurality of positions on the reference object that is located at a distance from the light source corresponding to the distance of the biometric target from the light source, wherein a fitting represented by a computation formula I r, z x, y = A x, y / D r 2 + B x, y / D r + C x, y is performed based on the luminance value of the reference object at each of a plurality of heights, where I r,z(x, y) denotes a luminance value at a coordinate (x, y) of the reference object obtained as a result of the fitting, D r denotes the distance from the light source to the reference object in a case in which the reference object is located at a height Z, and A(x, y), B(x, y), and C(x, y) denote coefficients of the computation formula of the fitting at positions corresponding to the point (x, y) on the captured image, and a coordinate (X, Y, Z) of the reference object corresponding to the coordinate (x, y) on the captured image is obtained from formulas X = Z / f ⋅ x Y = Z / f ⋅ y where f denotes a focal distance of a lens of the imaging apparatus, and the distance D r from the light source to the reference object is obtained from a formula D r x, y = X 2 + Y 2 + Z 2 1 / 2. a storage unit configured to store a correction coefficient for each of a plurality of positions on a reference object, with respect to each distance from the light source to the reference object; a luminance computing unit configured to compute a luminance at each of a plurality of positions on the biometric target within the captured image; a distance measuring unit configured to measure a distance from the light source to the biometric target; and a process unit configured to correct the luminance at each of the plurality of positions on the biometric target within the captured image, based on the correction coefficient at each of the plurality of positions on the reference object that is located at a distance from the light source corresponding to the distance of the biometric target from the light source, wherein a fitting represented by a computation formula I r, z x, y = A x, y / D r 2 + B x, y / D r + C x, y is performed based on the luminance value of the reference object at each of a plurality of heights, where I r,z(x, y) denotes a luminance value at a coordinate (x, y) of the reference object obtained as a result of the fitting, D r denotes the distance from the light source to the reference object in a case in which the reference object is located at a height Z, and A(x, y), B(x, y), and C(x, y) denote coefficients of the computation formula of the fitting at positions corresponding to the point (x, y) on the captured image, and a coordinate (X, Y, Z) of the reference object corresponding to the coordinate (x, y) on the captured image is obtained from formulas X = Z / f ⋅ x Y = Z / f ⋅ y where f denotes a focal distance of a lens of the imaging apparatus, and the distance D r from the light source to the reference object is obtained from a formula D r x, y = X 2 + Y 2 + Z 2 1 / 2.