An image captured by successive imaging over time by using a capsule endoscope is correlated with the imaging position and compiled into a database. The left side of a display screen of a monitor device displays a subject internal model, a trajectory path of the capsule endoscope, and a position mark indicating the imaging position. An image corresponding to the position of the position mark is displayed in an image display area on the right side. When a position mark on the trajectory path is designated by a mouse, the corresponding image is displayed. It is also possible to designate a section for which the image corresponding to the position mark is displayed or to designate a position mark where an unusual image is captured.