An ultrasound inspection apparatus includes a region setting section setting a plurality of regions within the inspection object; a sound velocity calculator calculating a sound velocity of each of the plurality of regions; a sound velocity obtainer obtaining a preliminary sound velocity of a region of interest; and an image quality determiner determining an image quality of the region of interest based on the preliminary sound velocity. The preliminary sound velocity obtained by the sound velocity obtainer is employed as a sound velocity of the region of interest when a determination result made by the image quality determiner is positive, and the sound velocity of the region of interest is calculated by the sound velocity calculator when the determination result is negative.