PURPOSE: To simultaneously control the finishing state and deformation of an operation object by constituting the processes of the contact and deformation of a controlled system and the operation object as a machine impedance model and controlling a deformation process.

CONSTITUTION: The model of the contact process of the controlled system and the operation object and the deformation process of the operation object are constituted as the machine impedance model for which the position and speed of the controlled system to the operation object are amounts relating to balance. Then, a system 7 provided with the controlled system and the operation object detects force F applied to the operation object by the controlled system and the position X and the velocity V of the controlled system to the operation object, inputs the target position and target velocity of the controlled system to the operation object and controls the position and the velocity. In this case, the target velocity Vd and target displacement Xd are respectively the solutions of the relocity and displacement of the machine impedance model and are the parameters of the velocity and the displacement to be obtained by the sliding part of the system 7 and target force Fd is the parameter of the force applied to the operation object by the controlled system.