PROBLEM TO BE SOLVED: To effectively suppress noises in an ultrasonic diagnostic apparatus that transmits ultrasonic waves to the inside of a subject, receives reflected back ultrasonic waves to obtain received signals, and displays a tomographic image of the inside of the subject on the basis of the received signals.SOLUTION: The present invention calculates a dispersion value of the signal value of each pixel in each of a plurality of depth regions which are regions divided according to the depth from a subjects surface with an ultrasonic wave probe applied while calculating a dispersion value of the signal value of each pixel in an entire region into which the plurality of depth regions are integrated. The invention then calculates a normalized dispersion value which is a ratio of the dispersion value for each of the plurality of depth regions to the dispersion value for the entire region, converts a normalized dispersion value for each of the plurality of the depth regions into a correction function value for each of the plurality of the depth regions on the basis of a correction function of a continuous curve which monotonously increases from a correction function value to decrease brightness to a correction function value to increase the brightness as the normalized dispersion value increases, with the normalized dispersion value as a variable to thereby calculate a correction value derived from the correction function value.
