A display unit displays data to be processed. The display unit is capable of displaying a plurality of windows for displaying the data therein. A controller outputs the control data to display the plurality of windows and an indicia on the display unit. An operating unit supplies the controller with a position signal to move the indicia to a desired location. An area unit checks whether the indicia is located a predetermined window area of the windows being displayed on the display unit, any data displayed in the predetermined window area being processed prior to the data displayed in any other window area. A specifying unit supplies signals to the controller, the signals specifying, in accordance with the check results made by said area check unit, a condition in which the indicia is displayed to demonstrate whether the indicia is being displayed in the predetermined window area or in the other window areas.