A lens barrel comprises a fixed barrel; a photographing lens which requires a first torque for driving the lens along the fixed barrel; and a surface wave motor including a fixed body and a moving body which is rotated relative to the fixed body by excitation for driving the lens. When the motor is not excited, a second torque is exerted between the moving body and the fixed body to prevent the relative rotation. The moving body is caused to rotate by a torque greater than the second torque. A friction generating device provided between the fixed barrel and the fixed body exerts a third torque to prevent relative rotation between the fixed barrel and the fixed body. The fixed body can rotate with respect to the fixed barrel only when the fixed body is caused to rotate by a torque greater than the third torque. A manual operation member drives the photographing lens by a manual operation; and a friction clutch provided between the manual operation member and the fixed body exerts a fourth torque. The manual operation member can rotate with respect to the fixed body only when caused to rotate by a torque greater than the fourth torque.