PURPOSE: To enlarge and display a root symbol, etc., in a beautiful shape having an optional aspect ratio.

CONSTITUTION: A font storage part 3 is stored with the root symbol while the symbol is divided into a feature part including a slanting line from the left and a straight part consisting of a right-side lateral line. Then when the input of the root symbol is commanded on a keyboard 1, a processing part 2 reads the feature part containing the left-side slanting line and the right-side straight line part separately out of the font storage part 3. Then the left-side feature part is enlarged longitudinally and laterally to the same scale factors and the right-side straight line part is enlarged longitudinally and laterally to different scale factor so that the specified aspect ratio is obtained on the whole. Consequently, the root symbol which is laterally long in the beautiful shape can be displayed.