An endoscope system computes a distal end position of the endoscope or a position of the desired imaging target. An image taken of the desired imaging target is recorded. A position of the desired imaging target is computed and recorded. A current image taken by the imaging unit is compared with the image of the desired imaging target already recorded. A first driving amount for driving the field-of-view adjustment mechanism is computed such that the desired imaging target is positioned on an axis of sighting of the imaging unit. A second driving amount for driving the field-of-view adjustment mechanism is computed in such a way as to include a center of the image of the desired imaging target. The field-of-view adjustment mechanism is driven from either one of the first driving amount or the second driving amount.
