A surgical instrument includes an extension portion having a surgical tool at an end thereof, and a head portion connected to the extension portion and actuating the surgical tool. In the surgical instrument, the extension portion includes a first extension portion connected to the head portion, a second extension portion having an elbow joint portion that is bending-actuated by a rigid rod that is reciprocated in a lengthwise direction by the head portion, and a connection portion connecting the first and second extension portions at an angle.
