An ultrasonic diagnostic apparatus includes an image generating unit configured to generate a plurality of different ultrasound image data items from reception signals corresponding to a plurality of different steering angles, on the basis of the reception signals which an ultrasound probe has generated on the basis of reflected ultrasonic waves received from a reflecting surface of a subject body by transmitting ultrasonic waves at the plurality of different steering angles, and a regression estimate generating unit configured to perform regression analysis on the basis of the different steering angles and the ultrasound image data items, and generate regression estimates which are weighting values on the basis of the result of the regression analysis, and an image synthesis unit configured to perform weighting on the plurality of ultrasound image data items on the basis of the regression estimates, and synthesize them, thereby generating synthetic image data.