The surgical treatment tool includes a housing, a shaft, an end effector that bends with respect to the shaft, a rotor that rotates about an axis of a rotation axis by an operation input that causes the end effector of the operation member to perform the bending operation, A transmission member that transmits a driving force for causing the end effector to perform the bending operation to the end effector. The operation member, the rotor, and the transmission member rotate together with the shaft and the end effector by an operation input that rotates the shaft and the end effector.
