PROBLEM TO BE SOLVED: To provide a technology capable of suppressing the influence of an error due to a movement of a subject in a subject information acquisition device for acquiring a photoacoustic signal by using light of a plurality of wavelengths.SOLUTION: A subject information acquisition device is used. The subject information acquisition device includes a light source part for irradiating pulse light of a plurality of wavelengths, a wavelength control part for switching wavelengths of the pulse light, a probe for receiving acoustic waves generated in a subject irradiated by the pulse light to propagate, a scan control part for moving the probe within a prescribed scanning range, and an information processing part for acquiring subject information by using a plurality of electric signals corresponding to the pulse light of a plurality of wavelengths, outputted from the probe at each receiving position within the scanning range. The wavelength control part switches wavelengths of the pulse light before the probe scans the entire scanning range while receiving acoustic waves corresponding to the pulse light of at least one wavelength among the plurality of wavelengths at each receiving position.SELECTED DRAWING: Figure 5
