An object information acquiring apparatus comprising: a receiver in which a plurality of elements is arranged, each of the plurality of elements receives an acoustic wave propagating from an object and outputs an electric signal a scanner configured to move the receiver through a predetermined scanning region an information processor configured to acquire characteristics information on an interior of the object using the electric signal and an acoustic attenuator configured to be arranged between the receiver and the object in the scanning region and have an acoustic attenuation characteristics distribution corresponding to a shape of the object is used.
