The present invention uses an object information acquiring apparatus having: an optical transmitter that transmits light and emits the light to an object； a first optical meter disposed at the incidence side of the optical transmitter； a second optical meter disposed at the emission side of the optical transmitter； a calculator that calculates an equation that indicates the relationship between the fluence of light measured by the first optical meter and the fluence of light measured by the second optical meter； a probe that receives an acoustic wave that is generated from the object due to the light emitted by the optical transmitter and converts the acoustic wave； and a processor that acquires specific information about the inside of the object.
