The postoperative cavity made by intact canal wall tympanoplasty for aural cholesteatoma was observed by inserting an aural attico-antroscopy (3A-scopy), developed by improving the antroscope for observations of the maxillary sinus, through a small incision made in the retroauricular region under local anesthesia. The 3A-scopy was effective in postoperative observations of the cavity which had undergone intact canal wall tympanoplasty, especially in the diagnosis of recurrent or residual cholesteatoma and in the observation of the postoperative cavity in the cases with long-standing discharge.