PURPOSE: To prepare a document accordant with the intention of a preparing person by equipping the title device with a document preparing mechanism to input characters and execute editing work, a cursor means to move between character strings, and an instructing means for designating the number of line boundary character check columns.

CONSTITUTION: The device is equipped with the document preparing mechanism to input the character and execute the editing work, the cursor means to move between the character strings, and the instructing means for designating the number of line boundary character check columns. Consequently, a format obtained by executing line boundary character check processing can be obtained for lines after a current line by inputting the characters, after that moving a cursor to a line for which line boundary character check is to be designated, selecting a menu for setting the number of the line boundary character check columns there, setting the number of the columns, and defining the document. Thus, the document accordant with the intention of the document preparing person can be prepared.