In photoacoustic imaging, the subject that can be accurately obtain the optical characteristic value to provide information acquisition device and subject information acquisition method. Subject information acquiring device according to the present invention, based on the sensitivity distribution of the plurality of acoustic wave detecting device, and a setting section for setting a predetermined sensitive region corresponding to each of a plurality of acoustic wave detecting element, a predetermined sensitivity range use the acoustic wave detecting element that does not contain a region of interest is obtained, without using a detection signal corresponding to the region of interest, an initial sound pressure acquiring unit that acquires an initial sound pressure in the region of interest, an initial sound pressure obtaining section Based on the detection signals have, by using a light intensity value obtaining unit for obtaining the integrated light quantity values in the region of interest, an initial sound pressure acquiring unit is acquired initial sound pressure, and the integrated light quantity value of the light quantity value acquiring unit has acquired and, It has a signal processing means comprising, an optical characteristic value obtaining unit for obtaining an optical characteristic value in said region of interest.光音響イメージングにおいて、光学特性値を精度良く取得することのできる被検体情報取得装置及び被検体情報取得方法を提供する。 本発明に係る被検体情報取得装置は、複数の音響波検出素子の感度分布に基づき、複数の音響波検出素子のそれぞれに対応する所定の感度領域を設定する設定部と、所定の感度領域に関心領域が含まれていない音響波検出素子が取得した、関心領域に対応する検出信号を用いずに、関心領域における初期音圧を取得する初期音圧取得部と、初期音圧取得部が用いた検出信号に基づき、関心領域における積算光量値を取得する光量値取得部と、初期音圧取得部が取得した初期音圧と、光量値取得部が取得した積算光量値と、を用いて、前記関心領域における光学特性値を取得する光学特性値取得部と、を備える信号処理手段を有する。
