A laparoscopic surgical instrument includes a shaft and a head having a distal end to which a variety of surgical instruments are attached. The laparoscopic surgical instrument also includes a flexible joint installed between the shaft and the head a longitudinal-driving unit including a longitudinal-driving wire connected with both longitudinal ends of the head and a longitudinal-driving roller turning the longitudinal-driving wire and a transverse-driving unit including a transverse-driving wire connected with both transverse ends of the head and a transverse-driving roller turning the transverse-driving wire. The longitudinal-driving unit turns the flexible joint in the longitudinal direction, the transverse-driving unit turns the flexible joint in the transverse direction, and the shaft has a small diameter.
