To provide an ultrasonic diagnostic apparatus capable of calculating the physical quantity in which the elasticity of a living tissue is more accurately reflected for a calculation starting pixel.

Correlation windows W1 and W2 are set for two temporally different echo signals r(t) and s(t) on the same sound ray, and a physical quantity calculation part calculates the physical quantity on the elasticity of the living tissue. In calculating the physical quantity on the calculation starting pixel, the first target for calculating the physical quantity on one sound ray, the physical quantity calculation part calculates the physical quantity a prescribed number of times, and calculates the physical quantity in the second calculation and thereafter by determining a setting starting position sp of the correlation window W2 and a window width WD based on the physical quantity obtained in the last calculation of the physical quantity for one echo signal, and resetting the correlation window W2.