The conventional surgical technique has shown excellent clinical results in treating various kinds of spine disease. However, it has been closely associated with complications such as cosmetic issues due to scarring, paraspinal muscle damage, and chronic postoperative lower back pain. To overcome these drawbacks, a surgical technique using a tubular retractor has been widely adopted for procedures ranging from simple decompression to fusion. Furthermore, an endoscope that allows access to the lesion through a single portal has been developed. The first-generation endoscopes primarily focused on removing disc herniations through the body’s natural pathways like the neural foramen or interlaminar space. The clinical outcomes after endoscopic surgery were highly successful. Not resting on these achievements, the full endoscope has continued to evolve, now incorporating drills for bone work. This another advancement has expanded the scope of surgery to include the treatment of spinal stenosis through internal decompression, and full endoscopic fusion is also being attempted. Despite these advancements in endoscopic spine surgery, the high cost of equipment, relatively narrow field of view, limited instrument maneuverability, and steep learning curve mean that mastery of these techniques, comparable to conventional open surgery, remains rare. To address the limitations of traditional endoscopy, the unilateral biportal endoscopy (UBE) technique has been developed. UBE has gained significant popularity and is now widely used around the world.