The present invention employs an object information acquiring apparatus including a plurality of light irradiators irradiating light from a light source to an object an intensity modulator modulating intensity of the irradiated light for each light irradiator a plurality of acoustic detectors detecting an acoustic wave generated from the object and an information processor producing internal characteristic information of the object by using the acoustic wave, wherein the information processor controls a weight of each acoustic detector in production of the characteristic information, based on the intensity of light in each light irradiator.