A photoacoustic apparatus includes a light source generating multiple lights with different wavelengths, a converting element receiving photoacoustic waves generated in a subject by the subject being irradiated by the multiple lights, a first distribution obtaining unit obtaining a property distribution based on optical absorption within the subject, for each of the mutually different wavelengths, using time-sequence reception signals each output from the converting element for each of the mutually different wavelengths, a second distribution obtaining unit obtaining, using multiple property distributions based on optical absorption for each wavelength, a concentration-related distribution of a substance of an object region of the subject, and a statistical information obtaining unit obtaining statistical information indicating variance in distribution in at least part of the concentration-related distribution.
