A fluorescence detection device is configured to detect a fluorescent substance which is attached to an inspected medium and glows at a specific wavelength. The detection device includes an illumination device configured to apply excitation light for exciting a fluorescent substance to an inspected medium, a first photoreceptor configured to receive excited light from the fluorescent substance of the inspected medium and detect only light of a specific wavelength, a second photoreceptor configured to receive excited light from the fluorescent substance of the inspected medium and detect light in a wider frequency band including the specific wavelength, and an authentication section configured to authenticate the fluorescent substance based on detection signals from the first and second photoreceptors.