An endoscope system, serving as a double-balloon endoscope system, includes an endoscope apparatus for examinations using an endoscope, a shape detection apparatus used in combination with the endoscope apparatus, and a balloon controller. The shape detection apparatus detects positions of respective points in an insertion section of the endoscope, estimates the shape of the insertion section on the basis of the detected positions, and displays an image representing the modeled shape of the insertion section corresponding to the estimated shape. The balloon controller controls balloons, serving as insertion support units, attached to the endoscope. The shape detection apparatus detects the states of the balloons controlled through the balloon controller and reflects the controlled states of the balloons on an image representing the shape of the insertion section. With this arrangement, the inflation/deflation states of the balloons and the insertion state can be visually confirmed in real time with ease.