PURPOSE: To recognize and learn handwritten marks with high precision by inputting the handwritten mark by digitizing it, generating a window at a display device at the time of the execution of a prescribed command in order to input plural handwritten marks.

CONSTITUTION: Data are written in an input screen 18 by using a stylus 16, generated coordinate information is inputted through an interface circuit 64 of the input screen to a computer 14, and transmitted through an input bus 52 to a micrprocessor 50 which executes programs stored in an ROM 54 and an RAM 56. Then, edition marks used by a specific writer for insertion, deletion, movement, and reformatting are learned, and those marks are converted into a digital command function. Then, handwritten marks written by using a single computer screen and corresponding font marks are displayed on adjacent windows. Therefore, a user can see the prescribed insertion or change of a text which is being edited without largely moving his or her head and eyes.