A surgical instrument includes a first jaw and a second jaw serving as grasping parts, a first joining part (54a), a first dissecting part (55a), a second joining part (54b), a second dissecting part (55b), and a tissue preservation part (56) disposed between the first joining part (54a) and the second joining part (54b) and configured to preserve a non-joining region between the first joining part (54a) and the second joining part (54b) when the first joining part (54a) and the second joining part (54b) join living body tissue.
