PROBLEM TO BE SOLVED: To provide a concentration measuring device capable of obtaining a concentration of a predetermined substance contained in a living body with high accuracy. SOLUTION: The concentration measuring apparatus of the present invention emits first light and second light to a first substance to be measured and a second substance distributed around the first substance in a larger amount than the first substance, respectively. A light irradiation unit to irradiate, an acoustic wave detection unit that detects the first acoustic wave and the second acoustic wave generated from the first substance and the second substance irradiated with light, and a signal based on the acoustic wave. Using a database in which the relationship with the concentration of a substance that generates an acoustic wave is recorded, and a second signal based on the second acoustic wave, the concentration of the first substance corresponding to the first signal based on the first acoustic wave is obtained. It has a signal processing unit for estimating. [Selection diagram] Fig. 1【課題】生体内に含まれる所定の物質の濃度を、高い精度で得ることが可能な、濃度測定装置を提供する。【解決手段】本発明の濃度測定装置は、測定対象となる第一物質、前記第一物質の周囲に前記第一物質より多く分布する第二物質に対し、それぞれ第一光、第二光を照射する光照射部と、光照射された前記第一物質、前記第二物質から、それぞれ発生する第一音響波、第二音響波を検出する音響波検出部と、音響波に基づく信号と、音響波を発生させる物質の濃度との関係が記録されたデータベース、前記第二音響波に基づく第二信号を用い、前記第一音響波に基づく第一信号に対応する前記第一物質の濃度を推定する信号処理部と、を有する。【選択図】図１
