A photoacoustic apparatus includes a light source; a receiving element configured to receive, at a plurality of positions, a photoacoustic wave generated through irradiation of a subject with light generated by the light source, and output a time-series reception signal; a signal data obtaining unit configured to obtain information that is based on a shape of the subject, generate reception signal data by reducing a data amount of the time-series reception signal on the basis of the obtained information that is based on the shape of the subject, and store the reception signal data; and an information obtaining unit configured to obtain information about the subject on the basis of the reception signal data stored in the signal data obtaining unit.