Abstract: A control apparatus comprising a cylinder including therein a piston non-stepwise controllable in terms of the amount of piston portion protruded and the speed of its protruding movement. The amount of piston portion protruded is controlled by an attachment position at which the cylinder is attached to an adaptor for fastening the control apparatus to a device desired to be controlled and the position of a bar extended into the cylinder through one end portion thereof to abut against a piston head. The speed of protruding movement of the piston is controlled by a control fluid fed into and discharged from a cylinder chamber divided by the piston head into two parts.