A surgical instrument has an insertion section, an operation section disposed in a proximal end of the insertion section, and a treatment section disposed in a distal end of the insertion section. First and second driving rods are disposed in the insertion section. The operation section is opened/closed and rotated to transmit an opening/closing force to the first driving rod, and a rotating force to the second driving rod. The treatment section comprises a pair of jaws. The treatment section is connected to the distal end portions of the first and second driving rods disposed in the insertion section to rotate and open/close the pair of jaws with respect to the insertion section.