1. A medical image display apparatus comprising: an ultrasonic probe configured to generate ultrasonic waves to impinge onto a three dimensional region of an object with the ultrasonic waves, and to receive reflected ultrasonic waves from the three dimensional region of the object; a control processor configured to generate data of a three dimensional image based on the reflected ultrasonic waves from the ultrasonic probe; a memory configured to store data of the three dimensional image; the control processor further configured to generate three slice images associated with three slices from the three dimensional image; a display configured to display the three slice images respectively in three display areas; the control processor further configured to generate three ROI (region of interest) markers to be respectively superimposed on the displayed three slice images, the three ROI markers corresponding to a single ROI; the control processor further configured to perform operation of changing relative positions between the three slice images and the three ROI markers; and the control processor further configured to move the three slice images in the three display areas in accordance with the operation of changing the relative positions and fix the three ROI markers at center positions of the three display areas; wherein the control processor is further configured to generate a confirmed ROI marker, based on an input from an operator, representing a confirmation that the ROI markers includes the ROI, to fix the confirmed ROI marker relative to the slice image, and to move the confirmed ROI marker in the display area together with the slice image.