To provide an image display controller which, when switching an image while fixing display magnification, can display the ranges corresponding to images before and after switching, and which reduces a possibility of the protrusion of a range of display from the whole of the images.

The image display controller comprises: a display control means of performing control so as to fix the magnification on the basis of a display resolution, and display a range of a part of the image on a display area of a display device; a memory means of determining a reference point 1206 based on the sides or points each furthest in a horizontal direction and a perpendicular direction from the center of the whole of the image A1 out of a display range 1204 in the image A1, and storing the relative position information indicating the relative position of the reference point 1206 in the whole of the image A1; and a display range determination means of determining the display range in the image B1 in such a manner that the relative position in the whole of the image B1, of a point corresponding to the reference point 1206 indicated by the relative position information is the relative position indicated by the relative position information.