The present technology relates to an endoscope apparatus configured to be capable of assisting with setting of an angle of view of immediately before an endoscope is pulled out when the endoscope is pulled out and cleaned and then reinserted during surgery in endoscopic surgery and the like, and a method and program for operating the endoscope apparatus.An image captured by the endoscope apparatus is recorded, a feature value of the image captured is detected, a difference between detected feature values of consecutive images is obtained, and, when the difference is greater than a predetermined threshold value, an index is added to the image captured. Thus, the index is added to an image of immediately before the endoscope is pulled out from a body cavity, and the image is recorded. Then, when the endoscope is pulled out and then reinserted, the images each to which the index is added are displayed as a list, and information indicating an angle of view in an image selected is displayed to be superimposed on information indicating an angle of view of an image currently captured after reinsertion, whereby assist display to an original angle of view is obtained. The present technology can be applied to the endoscope apparatus.
