A living body determination device includes: a light irradiation device that irradiates a measuring object with a first light including a plurality of spectrums; a spectroscopic device that disperses a light at intensity depending on a wavelength and outputs the light; an image acquisition device that receives the light output by the spectroscopic device and outputs image information representing brightness depending on the intensity of the light; and a control unit. The control unit, for each spectrum of the first light, acquires image information with respect to the measuring object from the image acquisition device, based on the image information, selects one or more areas, for each of the areas, acquires spectroscopic information, and based on whether the spectroscopic information satisfies a predetermined condition, determines whether the measuring object is a living body.