An ultrasonic diagnostic apparatus is provided with: an ultrasonic probe which is brought into contact with an object to transmit and receive ultrasonic waves a transmission unit and a reception unit which periodically transmit and receive the ultrasonic waves to and from the object and subject a reflection echo signal from the object to reception processing a displacement measurement unit which sequentially finds the displacements of a living organism tissue at the position of cross section at which the ultrasonic waves are transmitted to and received from the object an elasticity image construction unit which sequentially constructs the elasticity images of the living organism tissue and a three-dimensional image construction unit which constructs a three-dimensional elasticity image.
