A 61-year-old male was found to have a tracheal tumor, which was noted at the time of screening by a chest X-ray study. The tumor arose from the membranous portion 4 cm above the carina and was proven by biopsy to be a leiomyoma. Because the disease is a benign tumor, all methods for resection, including bronchoscopic techniques, were thus considered. We performed an endotracheal operation via a window made by an incision of the cartilagenous portion, and removed the tumor through an anterior approach. This type of endotracheal operation is one of the surgical procedures for the removal of benign tracheal tumors.