An ultrasound diagnosis apparatus that can acquire ultrasound image data of an excellent spatial resolution and contrast resolution by electrically controlling focusing points of transmission/reception waves so as to form transmitting beams and receiving beams having a substantially uniform thin beam width along elevation direction in an object. Transmission ultrasounds emitted from a prescribed number of transducers are focused at a hypothetical point sound source. Transmitting wave-fronts propagated from the point sound source reflect at a plurality of observing points in the propagation area. Reception ultrasounds reflected at the observing points are received through a prescribed number of receiving transducers so as to generate a plurality channel of receiving signals. The receiving signals are focused by performing receiving phase compensation and summation so that the observing point becomes a reception focusing point. The phase compensated and summed receiving signals are focused by performing wave-front phase compensation and summation in order to correct transmitting delays due to the propagation distances between the transmitting focusing point to the observing points.
