A photoacoustic apparatus according to the present invention is a photoacoustic apparatus for obtaining image data based on an acoustic wave generated by irradiating an object with light of a first wavelength and light of a second wavelength which is different from the first wavelength, the photoacoustic apparatus including a processing unit configured to: obtain a first image data group corresponding to the first wavelength generated based on an acoustic wave generated by irradiating the object with light of the first wavelength a plurality of times, obtain first positional deviation information corresponding to an irradiation timing with the light of the first wavelength on the basis of a first image data group corresponding to the first wavelength, and obtain second positional deviation information corresponding to an irradiation timing with the light of the second wavelength on the basis of the first positional deviation information.
