A medical diagnostic apparatus includes: a feature calculating unit configured to calculate a plurality of kinds of features that is based on luminance information or frequency spectrum information obtained from a received signal from a specimen, and that relates to attributes of a tissue of the specimen a classification unit configured to: classify the attributes of the tissue of the specimen by using a feature determined among the plurality of kinds of features calculated by the feature calculating unit according to a classification item selected in advance from a plurality of classification items assigned for each classification purpose and assign visual information according to a classification result to pixels of an image based on the received signal and a feature image data generating unit configured to generate feature image data on which the visual information assigned to the pixels of the image based on the received signal is superimposed.