A photoacoustic apparatus comprises a light source； an irradiation unit configured to radiate light from the light source to an object that contains a contrast agent； a receiving unit configured to receive acoustic waves generated when the contrast agent absorbs the light radiated by the irradiation unit and output an electrical signal； a correction processing unit configured to correct a signal strength of the electrical signal, based on a temporal change in a concentration of the contrast agent contained in the object； and an acquiring unit configured to acquire characteristics information on the object, based on the electrical signal that has been corrected by the correction processing unit.
