A substance detection device capable of detecting a specific component in a biological gas collected from the skin is realized.A substance detection device includes: a detection sample collection section which collects a biological gas released from the human skin, allows only this biological gas to pass through a permeable membrane, and stores the gas in a sensor chamber a light source which excites a Raman scattered light from acetone in the collected biological gas a sensor section which enhances the Raman scattered light by localized surface plasmon resonance a spectrometer which disperses the enhanced Raman scattered light a light receiving element a signal processing and control circuit section which compares the acquired spectrum with the fingerprint spectrum of acetone which has been stored in advance and thereby identifies acetone, which is the collected substance to be detected, and calculates the amount of fat burning having a correlation with the concentration of acetone and a display section.
