An object information acquiring apparatus comprises a light irradiation unit that irradiates an object with pulsed light a probe that converts an acoustic wave generated in the object due to first pulsed light into an acoustic wave signal a photo-detection unit that converts second pulsed light propagated through the object into an optical signal a frequency analysis unit that acquires a background optical coefficient with respect to the inside of the object on the basis of a predetermined frequency component of the optical signal a light intensity acquiring unit that acquires a distribution of light intensity of the first pulsed light reaching the inside of the object using the background optical coefficient and an information acquiring unit that acquires object information, using the acoustic wave signal and the distribution of light intensity.
