To provide a high resolution over an entire ultrasonic wave irradiation region and suppressing noise.SOLUTION: A transmission unit 1031 for making an ultrasonic transmission from a first transducer array of an ultrasonic probe 101 and a second transducer array in which the row center coincides with the row center of a first transducer array is selected A transmission time calculation unit 1043 that calculates a transmission time for ultrasonic waves to reach an observation point in the subject with respect to a plurality of observation points located within a range where the ultrasonic wave reaches A reception time calculation unit 1044 for calculating a reception time at which a reflected wave from the first transducer array reaches the second transducer array A delay calculator 1045, a delay processor 1046 for identifying a received signal value corresponding to the delay amount from the received signal sequence for each received oscillator, an adder 1048 for generating an acoustic line signal for the observation point based on the received signal value And I was painting.BACKGROUND OF THE INVENTION【課題】超音波照射領域全体にわたり分解能が高く雑音を抑制する。【解決手段】超音波プローブ101の第1の振動子列から超音波送信を行わせる送信部1031と、列中心が第1の振動子列の列中心と合致する第2の振動子列を選択する受信開口設定部1042と、超音波が到達する範囲内に位置する複数の観測点について、超音波が被検体中の観測点に到達する送信時間を算出する送信時間算出部1043と、観測点からの反射波が第2の振動子列に到達する受信時間を算出する受信時間算出部1044と、送信時間と受信時間との総伝播時間に基づいて各受信振動子に対する遅延量を算出する遅延量算出部1045と、各受信振動子に対する受信信号列から、遅延量に相当する受信信号値を同定する遅延処理部1046と、受信信号値に基づき観測点に対する音響線信号を生成する加算部1048とを備えた。【選択図】図1
