PROBLEM TO BE SOLVED: To provide a technique for preventing an imaging range from narrowing than a machine scanning range in an ultrasonic acquiring apparatus for performing image configuration by a synthetic aperture.SOLUTION: A subject information acquiring apparatus includes: a probe for electrically scanning a subject in a first direction and mechanically scanning in a second direction intersecting with the first direction； a first phasing and addition means for phasing and adding a received signal； a memory for storing a first phasing and addition signals for each tomographic plane in the second direction； a means for selecting signals corresponding to M tomographic planes from among the stored signals； a second phasing and addition means for phasing and adding the selected signals in the second direction； and a means for acquiring image data in the subject from the second phasing and addition signals. The second phasing and addition means, which is in accordance with mechanically scanning of the probe, includes a first case for fixing M signals and changing a delay pattern and a second case for changing a lot of the M signals and fixing the delay pattern.【課題】合成開口による画像構成を行う超音波取得装置において、撮像範囲が機械走査範囲より狭くなることを防ぐための技術を提供する。【解決手段】被検体を第一の方向に電子走査し、第一の方向と交差する第二の方向に機械走査されるプローブと、受信信号を整相加算する第一の整相加算手段と、第一の整相加算信号を第二の方向の断層面毎に格納するメモリと、格納された信号のうちＭ枚の断層面に対応する信号を選択する手段と、選択された信号を第二の方向に整相加算する第二の整相加算手段と、第二の整相加算信号から被検体内の画像データを取得する手段を有し、第二の整相加算手段は、プローブの機械走査に伴って、Ｍ枚の信号を固定し遅延パターンを変化させる第一のケースと、Ｍ枚の信号の組を変化させ遅延パターンを固定する第二のケースを切り替える被検体情報取得装置を用いる。【選択図】図３
