1. An ultrasonic diagnostic apparatus having an analyzing tool for analyzing lesion information of a tissue of an object by using RF signal frame data obtained from the object and a display, the analyzing tool comprising: at least one computer and memory, pre-configured to effect operations including: calculating displacement data by using RF signal frame data obtained in time-series; calculating elasticity data including at least one of distortion and elasticity modulus at each point of a cross-section of an object as an examination target by using the displacement data; generating elasticity image data of the cross-section of the object from the elasticity data; analyzing the elasticity data, and generating plural estimation data containing a histogram of the elasticity data, statistical processing data and shape complexity of a diseased tissue; selecting parameters concerning estimation data relevant for classifying the elasticity image; and multivariate-analyzing to classify the elasticity image into two or more groups by using the estimation data of parameters selected by the estimation data selector, wherein the display displays the elasticity image, the parameters used for classifying the elasticity image by the multivariate-analyzing, and a result of classification as classified by the multivariate-analyzing.