Positional information display system

A portable terminal device includes: a position detecting unit (1) for detecting device position on the basis of a GPS signal; an orientation detecting unit (2) for detecting device orientation by means of a flux gate type magnetic sensor (2) or another geomagnetic sensor; an arithmetically operating unit (CPU 6) for correcting the positional information detected by the position detecting unit (1) with orientation information from the orientation detecting unit (2); a map information storing unit (7) for storing map information therein; a positional information display unit (9) for displaying the present position on the basis of output from the arithmetically operating unit together with the map information; and a display processing unit (8) for subjecting the map information displayed by the positional information display unit (9) to rotary scrolling through an angle on the basis of orientation information from the orientation detecting unit (2) in accordance with orientation of the device at the present position. When the orientation is changed by the movement of the portable terminal device, the map information is rotated by the display processing unit (8), and the present position of the portable terminal device is displayed on a visual display portion (91) of the positional information display unit (9) so that the forward moving direction is always a predetermined specific direction within the visual display portion (91).