An endoscope system 1 includes an insertion portion 2b that is inserted into a subject, an objective optical window 11a provided on a distal end side of the insertion portion 2 to receive light from the subject, an image pickup device 11 that picks up an image of an interior of the subject, and a position/direction detection section 25 that acquires position information of the objective optical window 11a. The endoscope system 1 further includes a determining section that determines whether or not the subject image is an image that can be pasted based on image information or position information of a subject internal image acquired by the image pickup device 11 and an image pasting section that pastes the image determined to be the image that can be pasted onto a model image.