A subject information acquisition device includes elastic wave receiving means (300) configured to receive elastic waves generated inside a subject and output a reception signal and signal processing means (500) configured to acquire subject information in an interest region of the subject, on the basis of the reception signal. In measurement states, the elastic wave receiving means receives elastic waves and outputs reception signals corresponding to the measurement states. The signal processing means corrects the reception signals by weighting factors based on measurement parameters in the measurement states, and acquires corrected reception signals in the interest region corresponding to the measurement states. The signal processing means acquires the subject information in the interest region, on the basis of the sum of the corrected reception signals and the sum of the weighting factors.
