To inexpensively provide a two-dimensional coordinate detecting device, and especially to provide a plurality of two-dimensional coordinate inputting devices by one device, and to easily provide an input/output integral device where the display surface and input surface of a display device are united, and to execute the input/output integral input operation to a plurality of personal computers without altering the display device.

One or more two-dimensional input planes are set within the coordinate detecting space of a three-dimensional coordinate detecting device. Each input and output plane may be the display surface of a display device. Also, this input and output integral device is selectively connected to a plurality of computers so that the input/output integral input operations of the plurality of computers can be executed by one three-dimensional coordinate inputting device.