An ultrasound diagnostic apparatus includes: an image generator that generates ultrasound image data based on a reception signal obtained from a moving ultrasound probe; an evaluator that evaluates an index regarding suitability of combining a plurality of pieces of ultrasound image data generated by the image generator and generates an evaluation result; and a combiner that selects ultrasound image data according to the generated evaluation result and combines the ultrasound image data to generate panoramic image data.