A cross-sectional image display apparatus, method, and program is capable of setting cross-sectional positions consecutively and efficiently. 3D image data is stored in a PC, a two-dimensional image of the 3D image is presented at a position detection surface of a tablet, the three-dimensional image is virtually constructed in a space above the position detection surface to have dimensions corresponding to the two-dimensional image and to be located at a position corresponding to the two-dimensional image. A plate-like display device designates the cross-sectional position at which the cross-sectional image is to be displayed in the constructed 3D image, the tablet detects the designated cross-sectional position, the PC converts the detected cross-sectional position into a cross-sectional position in a coordinate system of the 3D image and creates cross-sectional image data, and the display device uses the cross-sectional image data to display the cross-sectional image.