An endoscopic system includes a sheath portion including an opening, a translucent balloon, an endoscope main body, and a display. The balloon includes a first index group having a plurality of balloon indices. Adjacent two of the plurality of balloon indices are different from each other. The balloon covers the opening and is configured to inflate and deflate. The endoscope main body is configured to be retracted into and projected from the opening. The endoscope main body is located inside the inflated balloon and is configured to observe an interior portion of a sinus. The display is configured to display an image obtained by the endoscope main body.
