Lines drawn on a touch screen with an inputting window opened are recognized as ruled lines which are parallel with a row or column of a spreadsheet, and a square formed by the ruled lines is set to a cell in the spreadsheet when the square is formed. Consequently, it is possible to create the spreadsheet when a user of a computer simply draws a line with a fingertip or the like over the touch screen, and furthermore, it is also possible to input a value to the cell by specifying the square part drawn with the lines to carry out an operation for inputting data. Thus, there is provided a spreadsheet creating interface which makes the most of a visibility and an operability of the touch screen.