PROBLEM TO BE SOLVED: To provide an ultrasonic image diagnostic apparatus displaying a reference image without imposing an operation burden on an operator while preventing lack of ultrasonic image information.SOLUTION: The ultrasonic image diagnostic apparatus includes: an ultrasonic image generation part generating an ultrasonic image from an ultrasonic probe an observation area setting part setting an observation area with respect to the ultrasonic image a reference image generation part generating a reference image corresponding to the ultrasonic image on the basis of position information from a position sensor connected to the ultrasonic probe a layout storage part storing display layout information showing that the reference image is placed in an area other than the observation area of the ultrasonic image a screen information setting part setting screen information including an arrangement position, an arrangement dimension, an image resolution, an image magnification ratio and an image center position for the reference image and the ultrasonic image, on the basis of the display layout information and a synthetic display part synthesizing the reference image and the ultrasonic image to display the synthesized image.
