An ultrasonic signal processing method includes: acquiring pieces of element data output from each element included in an ultrasonic probe including multiple elements configured to transmit an ultrasonic wave to a subject, receive an ultrasonic wave reflected by the subject and output an ultrasonic detection signal determining element data to be preserved, according to depth information on a reception echo at an acquisition time of the element data, among the pieces of element data of each of the acquired elements and preserving the element data determined to be preserved.
