Disclosed is a method for operating an ultrasonic diagnostic apparatus. The method includes transmitting separate first and second ultrasonic signals to an object, receiving a first echo signal which corresponds to the first ultrasonic signal and a second echo signal which corresponds to the second ultrasonic signal, separating the received first and second echo signals in order to generate first ultrasonic data which corresponds to the first echo signal and second ultrasonic data which corresponds to the second echo signal, and displaying a first ultrasonic image which is generated based on the first ultrasonic data and a second ultrasonic image which is generated based on the second ultrasonic data. The first ultrasonic image is an ultrasonic image of a first cross-sectional surface of the object, and the second ultrasonic image is an ultrasonic image of a second cross-sectional surface of the object.