A surgical device which is configured to apply energy to living tissue and to be used to perform a surgical procedure includes a grasping portion, an incising portion, an introduction portion and a treatment portion. The grasping portion grasps the living tissue having a first surface and a second surface. The incising portion is movable forward and backward with respect to the living tissue and incises the living tissue. The introduction portion is movable forward and backward with respect to the living tissue and introduces a biocompatible material, which is chemically bound with the living tissue, to a space between the first surface and the second surface. The treatment portion is configured to apply high-frequency energy and thermal energy to the living tissue.