A subject identification device includes: an illuminator configured to generate illumination light including components at a plurality of wavelength bands, each of the components having a characteristic in accordance with a respective one of settings; an imager configured to generate an image signal by capturing light from a subject under the illumination light having the illumination characteristic; and a processor including hardware. The processor is configured to: define an illumination characteristic of the illumination light; analyze the image signal to acquire spectral information of the subject; and cross check the spectral information of the subject with subject identification information in order to identify the subject. When the subject is not identified, the processor is configured to define another illumination characteristic that causes spectral information of potentials for the subject to be identified, and subsequently each of the imager and the processor performs a process.