Provided is an object information acquiring apparatus including: a detector that detects an acoustic wave which is generated from an object irradiated by light with a first wavelength and light with a second wavelength, and outputs an electric signal； a processor that determines a weight coefficient in accordance with concentration of a specified substance inside the object in use of a first signal, which is an electric signal derived from the light with the first wavelength, and a second signal, which is an electric signal derived from the light with the second wavelength, and weights the electric signal outputted from the detector； and a generator that generates specific information inside the object based on the weighted electric signals.
