A fundus image is displayed, which enables accurate positioning and focusing to be easily performed with respect to an eye to be examined even on a small display unit by selecting a display magnification. At a first display magnification, an opening portion “m” of a mask specifying a predetermined angle of field of the fundus is displayed with no part missed in both of horizontal and vertical directions of a display unit 15. At a second display magnification, the opening “m” of the mask is displayed with no part missed in the horizontal direction in the display area of the display unit 15 and with some part missed in the vertical direction. Thus, the second display magnification is used to observe an essential part when the fundus is accurately observed.