PURPOSE: To discriminate a color attribute clearly even on the screen of a display device which can not make a color display by switching fonts of characters according to an attribute for the modification of characters.

CONSTITUTION: An attribute code read out of a video RAM 24 is fetched to a font set selecting means 14 to select one font set CG0WCGn corresponding to the value of the code, thereby entering an access ready state. A font readout means 12, on the other hand, accesses the selected font set CG0WCGn according to a character code which is read out together and then data on the font corresponding to the attribute code is read out and sent by the front read out means 12 to a display display device 26 as image data. The character having different font according to the attributes is displayed. Consequently, the difference among color attributes is recognized clearly even on the character display device which can not make a color display.