A measuring apparatus, comprising: a probe having a plurality of elements each converting an acoustic wave into an electric signal, the plurality of elements being arranged at least in a first direction; a moving mechanism for moving the probe in a second direction crossing the first direction; a first delay and sum circuit for performing delay and sum in the first direction using a plurality of the electric signals obtained by the plurality of elements at individual positions along the second direction, so as to obtain a plurality of first add signals corresponding to a plurality of target points within individual cross-sectional planes in an object, wherein the cross-sectional planes are arranged successively along the second direction; a signal extraction circuit for letting an output from the first delay and sum circuit to pass through first and second delay circuits (23a, 23b), so as to output in parallel a plurality of the first add signals, wherein the first add signals output in parallel from the signal extraction circuit correspond to a same position within individual cross-sectional planes; a second delay and sum circuit for performing delay and sum using the plurality of first add signals output from the signal extraction circuit, so as to obtain second add signals; and an image processing circuit for generating image data inside the object by using a plurality of the second add signals corresponding to a plurality of individual target points, characterized in that the first and second delay circuits (23a, 23b) are cascaded, so that the output of the first delay and sum circuit is supplied to the second delay circuit and an output of the second delay circuit is supplied to the first delay circuit, wherein delay times of the first and second delay circuits (23a, 23b) are each set to a value corresponding to a scanning period of the probe for one cross-sectional plane. a probe having a plurality of elements each converting an acoustic wave into an electric signal, the plurality of elements being arranged at least in a first direction; a moving mechanism for moving the probe in a second direction crossing the first direction; a first delay and sum circuit for performing delay and sum in the first direction using a plurality of the electric signals obtained by the plurality of elements at individual positions along the second direction, so as to obtain a plurality of first add signals corresponding to a plurality of target points within individual cross-sectional planes in an object, wherein the cross-sectional planes are arranged successively along the second direction; a signal extraction circuit for letting an output from the first delay and sum circuit to pass through first and second delay circuits (23a, 23b), so as to output in parallel a plurality of the first add signals, wherein the first add signals output in parallel from the signal extraction circuit correspond to a same position within individual cross-sectional planes; a second delay and sum circuit for performing delay and sum using the plurality of first add signals output from the signal extraction circuit, so as to obtain second add signals; and an image processing circuit for generating image data inside the object by using a plurality of the second add signals corresponding to a plurality of individual target points, characterized in that the first and second delay circuits (23a, 23b) are cascaded, so that the output of the first delay and sum circuit is supplied to the second delay circuit and an output of the second delay circuit is supplied to the first delay circuit, wherein delay times of the first and second delay circuits (23a, 23b) are each set to a value corresponding to a scanning period of the probe for one cross-sectional plane.