An ultrasonic diagnostic apparatus includes reception circuitry, signal processing circuitry, and generating circuitry. The reception circuitry outputs a plurality of reception signals corresponding to respective reception scanning lines for each transmission and reception of an ultrasonic wave by an ultrasonic probe. The signal processing circuitry executes a weighting process and a phase correction process according to the position of each reception scanning line on at least one of the reception signals and a plurality of signals based on the reception signals, generates the processed signals for each reception scanning line, and outputs a plurality of composite signals using the processed signals generated based on the transmission and reception of the ultrasonic waves before and after changing the sound field of the transmitted ultrasonic wave, and before and after changing the position of the reception scanning lines. The generating circuitry generates a piece of image data based on the composite signals.