PROBLEM TO BE SOLVED: To accurately measure the quantity of a biological component in a living body.SOLUTION: The biological component-measuring instrument 1 includes: a sensor portion 2 to be inserted into the living body and a light-emitting portion 7 arranged in the living body in proximity to the sensor portion 2 and emitting excitation light to be emitted on a fluorescent substance causing fluorescence in accordance with the quantity of the biological component when it is irradiated with the excitation light by the interaction with the biological component present in the living body. The sensor portion 2 is provided with a light-receiving element detecting the fluorescence caused from the fluorescent substance and converting it to an electrical signal.COPYRIGHT: (C)2012,JPO&INPIT【課題】生体内の生体成分量を精度よく測定する。【解決手段】生体内に挿入されるセンサ部2と、センサ部2に近接して生体内に配置され生体内に存在する生体成分との相互作用によって励起光が照射されると生体成分の量に応じた蛍光を発生する蛍光物質に向けて照射する励起光を発する発光部7とを備え、センサ部2に、蛍光物質から発せられた蛍光を検出し電気信号に変換する受光素子が設けられている生体成分測定装置1を提供する。【選択図】図1