An ultrasonic image generation unit (25) for generating an ultrasonic image based on a detection signal of reflected ultrasonic waves by transmission of ultrasonic waves, and detecting the length direction of the puncture needle (15) based on the ultrasonic image It extends in the length direction of the puncture needle (15) by controlling the steering direction of the region of interest of the color Doppler measurement target based on the puncture needle detection unit (31) and the length direction of the puncture needle (15) A control unit (28) is provided to set an angle θ formed by the straight line and the straight line extending in the direction of the direction of interest to 0 ° ≦ θ <；90 °.超音波の送信による反射超音波の検出信号に基づいて超音波画像を生成する超音波画像生成部（２５）と、その超音波画像に基づいて、穿刺針（１５）の長さ方向を検出する穿刺針検出部（３１）と、その穿刺針（１５）の長さ方向に基づいて、カラードプラ計測対象の関心領域のステア方向を制御することによって、穿刺針（１５）の長さ方向に延びる直線と関心領域のステア方向に延びる直線とがなす角θを０°≦θ＜９０°とする制御部（２８）とを備える。
