Robot system includes robot main body including robot arm, end effector attached to robot arm, and force sensing device detecting force applied to end effector's tip end, actual reaction-force information generator generating force-sensing information according to force detected by force sensing device, and output force-sensing information as actual reaction-force information, virtual reaction-force information generator outputting force component detected by force sensing device, that has a magnitude proportional to time differentiation value, as virtual reaction-force information, adder configured to output information obtained by adding actual reaction-force information outputted from actual reaction-force information generator to virtual reaction-force information outputted from virtual reaction-force information generator, as synthetic reaction-force information, operating device outputting, when operator is made to sense a force according to synthetic reaction-force information outputted from adder and operator operates, operating information according to operation, and motion controller controlling robot main body's operation according to operating information outputted from operating device.