An ultrasonic diagnostic apparatus in which one of an imaging method with advantageous time resolution and an imaging method with advantageous spatial resolution can be selectively used according to an imaging object. The apparatus includes a transmission control unit for controlling a drive signal generating unit to scan the object while shifting a center position of a group of transducers, which simultaneously transmit ultrasonic waves, by a distance not larger than an interval of plural transducers in a first imaging mode and shifting a center position of a group of transducers, which simultaneously transmit ultrasonic waves, by a distance not less than twice the interval in a second imaging mode and an image generating unit for generating an image signal at a first frame rate in the first imaging mode and a second frame rate higher than the first frame rate in the second imaging mode.
