A substance detection device is realized whereby a specified constituent can be detected from living body gases collected from the skin. The substance detection device (1) comprises: a detection sample collection section (10) a light source a sensor section (31) a spectrometer (60) a photodetection element (70) a signal processing and control circuit (80) and a display section (130). The detection sample collection section (10) is accommodated in a sensor chamber (14) and collects living body gases emitted from the skin of a person and passes only these living body gases through a permeable membrane. The light source excites Raman scattered light from acetone in the living body gases that are collected. The sensor section (31) amplifies the Raman scattered light by localized surface plasmon resonance. The spectrometer (60) spectrally analyses the amplified Raman scattered light. The photodetection element (70) converts the spectrally analysed light to an electrical signal and acquires the spectrum of the amplified Raman scattered light. The signal processing and control circuit (80) compares the acquired spectrum with the fingerprint spectrum of acetone which is stored beforehand and thereby identifies acetone, which is the substance to be detected that has been collected, and calculates the amount of fat that has been burnt, which is correlated with the acetone concentration. The display section (130) displays the results calculated by the signal processing and control circuit (80).Linvention concerne un dispositif de détection de substance avec lequel un constituant spécifié peut être détecté à partir des gaz de corps vivant recueillis à partir de la peau. Le dispositif de détection de substance (1) comprend : une section de collecte déchantillon de détection (10) une source lumineuse une section capteur (31) un spectromètre (60) un élément de photodétection (70) un circuit de traitement de signal et de commande (80) et une section daffichage (130). La secti
