A subject information acquisition apparatus of the present invention includes a transmission/reception unit including a plurality conversion elements which transmit an elastic wave to the subject and receive a reflected wave that is reflected at each position in the subject, a scan line signal acquisition unit which acquires a plurality of signals corresponding to the reflected waves from each position in the subject as scan line signals by using a plurality of reception signals outputted from the conversion elements, and a processing unit which acquires moving information of the object by using the plurality of scan line signals. The processing unit acquires the moving information of the object on the basis of a distribution of cross-correlation values on a plane represented by two axes including an axis of time difference and an axis of distance difference by using a plurality of cross-correlation values between scan line signals at different positions.
