Zenker's diverticulum is a very rare disease among gastorointestinal diverticulum. We report a case of Zenker's diverticulum successfully treated with diverticulectomy and cricophalyngial myotomy. A 71-year-old male complained of aspirating water for two years. He was diagnosed as Zenker's diverticulum. Due to his severe symptoms, the operation was performed in an open-neck approach. The left recurrent laryngeal nerve was identified and preserved. An incision was made in the diverticulum wall, and the internal diameter of normal cervical esophagus was measured. The diverticulum was then excised with an automatic suture device in the minor axis direction of the esophagus. A cricopharyngeal myotomy was conducted, because this muscle was fibrotic and stiffened. The patient's symptoms disappeared after the operation. Diverticulectomy and cricopharyngeal myotomy through an open-neck approach is a safe and reliable method that follows, direct access to the diverticulum and recurrent laryngeal nerve.