An insertion needle 15 has a photoacoustic wave generating portion that generates a photoacoustic wave by absorbing light emitted from a laser unit 13. A photoacoustic image generation unit 25 generates a photoacoustic image based on the detection signal of the photoacoustic wave emitted from the insertion needle 15. The sound source position detection unit 30 detects the photoacoustic wave generating source from the photoacoustic image. A first signal acquisition unit 31 acquires an S value, and a second signal acquisition unit 32 acquires an N value. A light emission control unit 33 controls the number of light emissions and the light emission interval of the laser unit 13 for one photoacoustic image generation based on the ratio between the S value and the N value. The photoacoustic image generation unit 25 generates a photoacoustic image by at least adding the detection signals of photoacoustic waves corresponding to the number of light emissions.
