In endoscopic surgery, surgeons occasionally encounter difficulties due to visual field obstruction by muscles or blood vessels. In these situations, specialized instruments that can effectively retract these obstructions are required. Recently, we developed a new detachable wire-rimmed retractor (KN retractor) for narrow-space surgery. We evaluated the utility of this KN retractor in 15 patients with thyroid and parathyroid disease. Of those, five patients with papillary thyroid cancer had gasless endoscopic hemithyroidectomy with central node dissection, five underwent endoscopic total thyroidectomy for Graves' disease, and the remaining five received endoscopic parathyroidectomy with gas insufflation. Surgeons were able to perform meticulous operations in a satisfactory visual field supported by the KN retractor. In all patients, the strap muscles were preserved without cutting. The average operating time was 149, 154, and 81min in patients who underwent hemithyroidectomy with central node dissection, total thyroidectomy, and parathyroidectomy, respectively. Gas insufflation was successfully completed in all cases while maintaining sufficient airtightness. The KN retractor is suitable for both the gasless lifting method and gas insufflation surgery in a narrow space. We believe that the KN retractor is a new device that will greatly improve the safety and shorten the operation time in endoscopic surgery.