An object information acquiring apparatus, comprises a signal acquiring unit that acquires a signal obtained by converting, with an acoustic element, an acoustic wave generated from an object to which light is irradiated; an information acquiring unit that performs, on the acquired signal, a signal process including at least any of an input impedance matching process, a filtering process, an amplification process, a subtraction process, and a signal extraction process, and acquire characteristic information inside the object using the processed signal; and a form acquiring unit that acquires form information of the object, wherein the information acquiring unit determines, based on the form information, contents of the signal process to be performed on a signal corresponding to an acoustic wave arriving from a target region.