The present invention is directed to a bar code generator which improves a print quality of a bar code and further enhances reading precision thereof, as to both vertical and horizontal bar codes. In this bar code generator, bar width information is set independently for each of the vertical and horizontal bar codes, as a precondition for printing the vertical and horizontal bar codes, selectively. When the bar code is printed (S802), it is determined whether the bar code is vertical or horizontal (S803), and according to the result of the determination, the bar width information of the determined bar code orientation is read out for drawing an image of the bar code (S804, S805, and S806). The result being drawn is transmitted to the printer, and the bar code is printed.