An ultrasonic diagnostic apparatus includes an ultrasound probe having two-dimensionally arranged transducer elements for transmitting and receiving ultrasonic waves to an object, a transducer element selector for selecting transducer elements used in transmission and reception, a signal processing unit for applying a delay to a signal received by a selected transducer element, an image processing unit for generating an image based on the output signal of the signal processing unit, and an image display unit. The image processing unit stores a first ultrasound image obtained by a scan of a first transducer arrangement selected by the transducer element selector and a second ultrasound image obtained by a scan of a second transducer arrangement selected by the transducer element selector so as to irradiate an ultrasound beam in a different direction than the beam direction of the first transducer arrangement, and combines the first ultrasound image and the second ultrasound image.