PROBLEM TO BE SOLVED: To provide a technique in photoacoustic tomography for decreasing influence due to multiple reflection of photoacoustic wave generating from a surface of a subject.SOLUTION: A subject information acquisition device includes a light source generating light, light emission means including an emission end emitting the light to a subject, detection means detecting an acoustic wave generating from the subject irradiated with the light, processing means acquiring characteristic information inside the subject by using the acoustic wave, and absorption means constituted by a material absorbing the acoustic wave. The absorption means is provided between a surface of the subject and the emission end.
