A living body detection device comprising: an image acquisition unit that acquires, from an infrared camera, a first image in which a face region of a subject irradiated by light in a first wavelength range is imaged, a second image in which the face region of the subject irradiated by light in a second wavelength range is imaged, and a third image in which the face region of the subject irradiated by light in a third wavelength range is imaged, the second wavelength range being different from the first wavelength range, the third wavelength range being different from the first wavelength range and the second wavelength range; a face detection unit that detects a forehead region, a right cheek region, and a left cheek region of the face region from each of the first, second and third images; a determination unit that determines, for each of the forehead region, the right cheek region, and the left cheek region, whether luminance of the region imaged in the third image is lower by a first predetermined ratio than luminance of the region imaged in the first image, and determines, for each of the forehead region, the right cheek region, and the left cheek region, whether the luminance of the region imaged in the third image is lower by a second predetermined ratio than luminance of the region imaged in the second image; and a detection unit that detects whether the subject is human skin or silicone resin, wherein the detection unit detects that the subject is human skin when the determination unit has determined, for any one of the forehead region, the right cheek region, and the left cheek region, that the luminance of the region imaged in the third image is lower by the first predetermined ratio than the luminance of the region imaged in the first image and the luminance of the region imaged in the third image is lower by the second predetermined ratio than the luminance of the region imaged in the second image, wherein the first wavelength range is 1180 ± 50 nm, the second wavelength range is 1280 ± 50 nm, and the third wavelength range is 1500 ± 50 nm. an image acquisition unit that acquires, from an infrared camera, a first image in which a face region of a subject irradiated by light in a first wavelength range is imaged, a second image in which the face region of the subject irradiated by light in a second wavelength range is imaged, and a third image in which the face region of the subject irradiated by light in a third wavelength range is imaged, the second wavelength range being different from the first wavelength range, the third wavelength range being different from the first wavelength range and the second wavelength range; a face detection unit that detects a forehead region, a right cheek region, and a left cheek region of the face region from each of the first, second and third images; a determination unit that determines, for each of the forehead region, the right cheek region, and the left cheek region, whether luminance of the region imaged in the third image is lower by a first predetermined ratio than luminance of the region imaged in the first image, and determines, for each of the forehead region, the right cheek region, and the left cheek region, whether the luminance of the region imaged in the third image is lower by a second predetermined ratio than luminance of the region imaged in the second image; and a detection unit that detects whether the subject is human skin or silicone resin, wherein the detection unit detects that the subject is human skin when the determination unit has determined, for any one of the forehead region, the right cheek region, and the left cheek region, that the luminance of the region imaged in the third image is lower by the first predetermined ratio than the luminance of the region imaged in the first image and the luminance of the region imaged in the third image is lower by the second predetermined ratio than the luminance of the region imaged in the second image, wherein the first wavelength range is 1180 ± 50 nm, the second wavelength range is 1280 ± 50 nm, and the third wavelength range is 1500 ± 50 nm.