An object information acquiring apparatus including a receiver provided with: a plurality of detecting elements which receive an acoustic wave from an object and generate an electrical signal and provided with a container-shaped supporter which supports the plurality of detecting elements; and a tank which holds an acoustic matching liquid; and a flow path which connects the tank with a liquid inlet port and a liquid discharge port provided in the receiver, the object information acquiring apparatus further including: a liquid circulator which controls a flow of the acoustic matching liquid; a UV irradiator which irradiates the acoustic matching liquid with ultraviolet light onto; and a processor which uses the electrical signal to generate property information on the interior of the object.