To enable the seeing through of the map of a part which overlaps with a present place displaying symbol without shielding it by making the display color of the present place displaying symbol differe from the color of a map being a background and also performing a screen display while overlapping the present place displaying symbol with the map in a translucent state which the map being the background can be seen through.

A translucently displayed present place displaying symbol is made displayable by plotting the present place displaying symbol while using a CPU 6 or a plotting processor 10 having a function performing a plotting in an image memory for display 9 by specifying a translucency to a plotting color or a plotting attribution. That is, the display color of the present place displaying symbol is differed from the color of the map becoming the background and also the symbol is overlapped on the map in the state in which the map can be seen through. Thus, it can be dissolved that the map of a present place and the map of the neighbourhood of the place to which a user pays attention most are shielded by the present place displaying symbol. Moreover, since the present place displaying symbol itself is displayed in the translucent state, the confirmation of the present place is also easy.