A photoacoustic apparatus capable of reducing image unevenness generated due to a temporal change of a quantity of light output from a light source is provided. A photoacoustic apparatus according to the present invention includes a light source 2a which irradiates an inspection target with pulsed light, a detector 5 which detects acoustic waves generated in the inspection target 3 due to the pulsed light, a light-quantity measurement unit 8a which measures a quantity of the light output from the light source 2a, and a signal processor 15 which obtains information on an inside of the inspection target using detection signals obtained by the detector 5. A signal processor corrects intensities of the detection signals so as to suppress variations of the intensities of the detection signals caused by the temporal change of the output light quantity.
