A control device and a control method of a master-slave system and the master-slave system are provided. A control device, which controls an operation of a master-slave system, includes a control unit that applies, to a control system of the master-slave system, a restraint force corresponding to an operation in a desired translational or rotational direction by the master. The control unit applies, to the control system, the restraint force according to a difference between a current position or posture of the master and a reference value of a position or posture to be restrained. The control system controls the master-slave system, for example, by a bilateral control method or a unilateral control method.
