An ultrasonic diagnostic device includes an automatic contour extracting unit that contains an initial contour extracting unit for roughly extracting an initial contour of an object to be examined from an ultrasound image by performing a predetermined operation (such as equalization, binarization, and degeneration) on the ultrasound image. The automatic contour extracting unit also contains a dynamic contour extracting unit for accurately extracting a final contour of the object by using the extracted initial contour as an initial value and by applying an active contour model, such as the SNAKES model, to the object within the ultrasound image.