In the ultrasound diagnostic apparatus, the method of determining the sound velocity, and the program recorded in a recording medium, a probe is made transmit an ultrasonic beam a plurality of times so as to form a predetermined transmission focus point, an analog element signal output by the probe is A/D converted into the first element data, the second element data corresponding to any one of a plurality of the first element data is generated, and the second element data is used to determine the sound velocity in an inspection object, whereby the sound velocity of the ultrasonic waves in the inspection object can be accurately determined without decreasing the frame rate.
