Operating section provided on a base is displaceable, in response to operation by a human operator, relative to the base with respect to at least one displacement axis, such as one linear-displacement axis and two rotary-displacement axes. A plurality of pivot axes are provided in corresponding relation to the displacement axes of the operating section. Different pieces of reactive force information are generated in correspondence with the individual pivot axes, and a plurality of motors, provided in corresponding relation to the pivot axes, are driven on the basis of the respective reactive force information, to thereby impart a separate or different reactive force to the operating section for each of the displacement axes. Displacement of the operating section is detected for at least one parameter from among parameters including a position, angle, velocity and acceleration, to output a detection signal corresponding to the detected parameter.