PURPOSE: To contrive to improve the accuracy of a selecting area and to increase the number of selecting areas by displaying a reference point at a cathode ray tube and adjusting a screen position in relation to a touch panel.

CONSTITUTION: A screen position adjusting circuit 5 executes reference point displayings 13aW13d even at the outside of an operation displaying area 12 by a displaying control circuit 1 onto a tube surface 11 of a cathode ray tube 7. A deflecting voltage is made variable to a horizontal deflecting circuit 3 and a vertical deflecting circuit 4 so that the displaying signal of reference point displayings 13aW13d can be coincident to the position of photo diodes 10aW10d of a touch panel 8. Thus, a control signal to make variable the displaying size and the displaying position is respectively sent as HVADJ and VVADJ, and the photo diodes 10aW10d and the reference point displayings 13aW13d are made coincident. Thus, the position relation of the displaying area 12 and the touch panel 8 can be made always constant, the accuracy of the selecting area comes to be good and the number of the selecting areas can be also increased.