PROBLEM TO BE SOLVED: To automatically specify, when an object person watches an image, which part of the image the object person intentionally watches.SOLUTION: This attention degree detecting system 10 includes: a display device 12 for displaying an image an eyeball movement measuring device 13 for acquiring for each prescribed time, eyeball movement data of the object person who watches the image displayed on the display device 12 and an attention degree determination device 14 for determining an attention degree of the object person in the image based on the eyeball movement data acquired by the eyeball movement measuring device 13. The attention degree determination device 14 specifies the attention degree using a prestored mathematical expression at a time unit when a position of a watch point in the image and a pupil diameter are acquired as the eyeball movement data, based on a time course related to the watch point and the pupil diameter in a past time from the time.
