A photoacoustic measurement device capable of reducing artifacts caused by photoacoustic waves generated at a surface portion of a subject on which measurement light is incident, and a signal processing method thereof are obtained. A photoacoustic measurement device (10) includes region discrimination means (24) that discriminates an artifact generation region and an artifact non-generation region in a photoacoustic image on the basis of a positional relationship between a light emitting portion (40) and an acoustic wave detection portion (20), and filter means (24) for performing a first filtering process on a first photoacoustic wave detection signal corresponding to a photoacoustic image of the artifact non-generation region and performing a second filtering process on a second photoacoustic wave detection signal corresponding to a photoacoustic image of the artifact generation region. The second filtering process includes further reducing the photoacoustic wave detection signal in a frequency range lower than a predetermined frequency as compared with the first filtering process.
