The present invention relates to a minimally invasive surgical instrument having a shaft including an internal torque transmission member. According to one aspect of the present invention, the minimally invasive surgical instrument comprises a shaft, and an end effector connected to one end of the shaft. The shaft has at least one curved portion, and the at least one curved portion can transmit torque for operating the end effector in a rolling direction by means of a torque-transmission member therein.
