PROBLEM TO BE SOLVED: To realize high resolution, a high frame rate and a high SNR/dynamic range by providing the device with a wall filter compressing the fundamental signal component of a reception signal for band-pass and selectively passing the frequency corresponding to a surge energy reflector. SOLUTION: The same transmission series is fed to each pulser 24 N times from a memory 38 to feed pulses N times, and a transducer array 10 is controlled so that the generated ultrasonic energy is controlled in direction as a beam at each transmission firing. A transmission convergence time delay 36 is applied to each pulse wave-form. An echo signal is fed to each reception channel of a reception beam former at each transmission. Obtained echo signals are added, a synthetic echo signal is fed to a filter 46 serving a decoding/band- pass filter process action and a wall filter process action, and the filtered signal is fed to a detector 32.
