We report a successful application of a new submucosal dissection method for EMR using an endoscope equipped with a slit-hood and hook knife. The mucosal lesion is separated from the submucosal layer with the aid the hood and the submucosal fibers are cut with the hook knife introduced through the slit, allowing an easy and safe dissection with good visualization of the tissue. Twenty-seven patients with early gastric cancer underwent EMR using a slit-hood and hook knife. Tumors were completely resected in 10 cases, and perforation of the stomach occurred in one case. The hook knife cuts as it is pulled back into the hood, helping to prevent perforation.