1. A method of processing information comprising: generating a sensor output signal responsive to the three-dimensional coordinate position of a detection target in a monitor space, and outputting the sensor output signal; detecting the three-dimensional coordinate position of the detection target in the monitor space from the sensor output signal; determining whether the three-dimensional coordinate position of the detection target in the monitor space is contained in a three-dimensional space region, based on the three-dimensional position of the detection target and stored coordinate information; and outputting the determination results obtained in the determining step, wherein the three-dimensional space region is placed within the monitor space, and set in accordance with the external surface of a three-dimensional object responsive to a pressing force, determining whether the three-dimensional object is under the pressing force of the detection target in response to a distance of the three-dimensional coordinate position of the detection target within the three-dimensional space region from a border of the three-dimension space region, determining the intensity of the pressing force responsive to the distance from the border, and outputting an output signal responsive to a difference in the pressing force.