A woman in her seventies was diagnosed with submucosal tumor on the lesser curvature of lower gastric body. The lesion increased in size and was histologically diagnosed as a gastrointestinal stromal tumor (GIST). Therefore, Endoscopic full thickness resection was performed using a scissor-type knife under general anesthesia. After the en block resection, the gastric defect was closed by Reopenable clip over-the-line method. The total procedure time was 67 min. The patient discharged uneventfully. Histological examination confirmed a low-risk GIST with free resection margin. Scissor-type knives are useful for safe and efficient procedures. They allow secure tissue grasping and soft coagulation, reducing device exchanges and bleeding risk. Their familiar grasp-and-cut mechanics also help lift the lesion away from surrounding tissue, minimizing injury.