A stopper apparatus for neutralizing rotary reaction force set up by the rotation of a casing in an all-casing driver, comprises a long transmission frame for transmitting the reaction force, including a base frame connected to a casing drive unit and a joint frame one end of which is connected to the base frame, and a support frame horizontal- and vertical-rotatably connected to the other end of the joint frame. At least one side of the support frame comes in contact with a supporting mass by which the reaction force is supported. The stopper apparatus also comprises a pedestal for placing a working wagon thereon, detachably connected to the transmission frame, an inclination device for raising the pedestal to an inclined position, and an inter-frame distance increasing device for increasing the wedge of the pedestal.