An endoscope system 1 includes an insertion portion 2b that is inserted into a subject, an objective optical window 11a that is provided on a distal end side of the insertion portion 2 and receives light from the subject, an image pickup device 11 that picks up an image of an inside of the subject, a position/direction detection section 25 that acquires position information of the objective optical window 11a, and a memory 22 that records the subject internal image acquired by the image pickup device 11 in association with the position information of the objective optical window 11a. The endoscope system 1 aligns the position information of the objective optical window 11a with a position of a predetermined organ in the subject in a coordinate system of a model image based on an amount of change or the like of the subject internal image information in the subject and generates an image with the subject internal image pasted onto the model image of the predetermined organ in which the position of the objective optical window is associated with the position in the coordinate system.
