PROBLEM TO BE SOLVED: To provide a method for acquiring an effect of high picture quality by aperture synthesis even when an imaging object moves.SOLUTION: An ultrasonic wave is transmitted to a range 33 which should be imaged of an imaging object 20 from a transmission opening 110 of an ultrasonic probe 108. An echo of the ultrasonic wave from the imaging object 20 is received by a reception area 130 of the ultrasonic probe, then phasing processing is performed on an output of the reception area 130, and acquiring a reception signal on a desired reception focus of the imaging object 20. A plurality of reception signals for a same reception focus are subjected to addition processing, the plurality of reception signals being acquired by a reception part 105 from the echoes of the ultrasonics transmitted at different transmission timings and from different transmission apertures 111. At this time, when the ultrasonics are transmitted, the ultrasonics are sequentially transmitted from the different plurality of transmission apertures 110, 111 at timings in which, a spatial position of the reception focus on the imaging object 20 matches according to movement of the imaging object 20 with respect to a same area out of the plurality of areas obtained by dividing the range 33 which should be imaged of the imaging object 20.SELECTED DRAWING: Figure 1【課題】撮像対象に動きがある場合であっても、開口合成により高画質化の効果を得る方法を提供する。【解決手段】超音波探触子１０８の送信開口１１０から撮像対象２０の撮像すべき範囲３３に向かって超音波を送信する。撮像対象２０からの前記超音波のエコーを超音波探触子の受信領域１３０によって受信し、受信領域１３０の出力に対して整相処理を施して、撮像対象２０の所望の受信焦点についての受信信号を得る。異なる送信開口１１１から異なる送信タイミングで送信された超音波のエコーから受信部１０５がそれぞれ得た、同一の受信焦点についての複数の受信信号を加算処理する。このとき、超音波を送信する際に、撮像対象２０の撮像すべき範囲３３を分割した複数の領域のうち同一の領域に対して、撮像対象２０の動きに応じて撮像対象２０における受信焦点の空間位置が一致するタイミングで、異なる複数の送信開口１１０，１１１から順に超音波を送信する。【選択図】図１
