To improve the ability to retrieve a taken image of aninternal body and to easily recognize the organ depicted ineach image, an average color bar 507 indicating the overallimaging period of images taken in time sequence by ancapsule endoscope is displayed, a movable slider S is shownon the average color bar 507, an image at the imaging timecorresponding to the position of the slider S is displayedand an average color based on taken image data is displayedat the time-associated position on the average color bar507.
