Abstract: A determination device includes an irradiator, an extractor, an imager, and a determiner, The irradiator irradiates an object including a food or a plant with a light. The extractor extracts a predetermined fluorescence emission having a predetermined wavelength out of fluorescence emissions generated from a surface of the object irradiated with the light. The imager captures a fluorescence image indicating the predetermined fluorescence emission. The determiner determines a state of the object based on an index indicating a fluorescence intensity of the fluorescence image.