PROBLEM TO BE SOLVED: To provide a photoacoustic apparatus having a new method for acquiring sound velocity information.SOLUTION: A photoacoustic apparatus includes light irradiation means 100 for irradiating light to a subject, reception means 400 for converting a photoacoustic wave generated from the subject to which the light from the light irradiation means is irradiated, to an electric signal, optical coefficient acquisition means 720 for acquiring optical coefficient information on the subject, sound velocity acquisition means 740 for acquiring sound velocity information on the subject using the optical coefficient information acquired by the optical coefficient acquisition means, and subject information acquisition means 730 for acquiring subject information using the electric signal and the sound velocity information.SELECTED DRAWING: Figure 1【課題】音速情報を取得する新規な方法を有する光音響装置を提供する。【解決手段】光音響装置は、光を被検体に照射する光照射手段１００と、光照射手段からの光が照射された被検体から発生する光音響波を電気信号に変換する受信手段４００と、被検体の光学係数情報を取得する光学係数取得手段７２０と、光学係数取得手段により得られた光学係数情報を用いて、被検体の音速情報を取得する音速取得手段７４０と、電気信号と音速情報とを用いて、被検体情報を取得する被検体情報取得手段７３０と、を有する。【選択図】図１
