To provide efficient use of light energy, in photoacoustic imaging.

This photoacoustic image generation device 10 includes: a light source part 13 outputting measurement light L; a light irradiation means irradiating the measurement light L to a subject M; a probe 11 having an ultrasonic transducer detecting a photoacoustic wave U generated inside the subject M by the irradiation of the measurement light L; a coordinate acquisition means sequentially acquiring coordinates in a real space of the probe 11; a control means 29 transmitting a first trigger signal to the light source part 13 when having acquired the coordinates satisfying a prescribed condition; and a photoacoustic image generation means generating a photoacoustic image about a photoacoustic signal based on the photoacoustic signal of the photoacoustic wave U detected by the probe 11. The light source part 13 outputs the measurement light L interlockingly with the reception of the first trigger signal.