This surgical instrument is provided with: an insertion section； first and second jaws； a bonding section configured to bond tissues grasped by the first and second jaws； a guide section formed along a predetermined curved shape and disposed at the first jaw； an actuation section having guided sections which are engaged with the guide section, a base which is continuous to the guided sections, and a blade section which is fixed to the base； and a dissection connecting member configured to extend from a proximal end portion of the guide section toward a distal end portion of the guide section when viewed along the guide section, to be turned back at the distal end portion of the guide section, to extend toward the proximal end portion of the guide section, and to be coupled to the actuation section.
