An ultrasonic diagnostic apparatus is provided with an ultrasonic probe driving section 2, a receiving section 5 for amplifying an ultrasonic reflected wave, a phase detecting section 6 for phase-detecting the ultrasonic reflected wave, a velocity computing section 10 for obtaining the velocity of an object to be measured at a plurality of measuring positions on the object to be measured from a phase-detected signal, a computing section 10 for obtaining the deformation amount and/or elastic module between measuring positions of the object to be measured from the velocity, a fluid determining section 9 for determining a fluid portion in the object to be measured in accordance with the phase-detected signal, and an image data generating section 72 for two-dimensionally image-displaying the deformation amount and/or elastic module of the object to be measured in a region other than the fluid portion by using the information determined by the fluid determining section.