The fluorescent display tube is of the flat tube type driven by a dynamic drive system. The tube comprises a transparent envelope made up of a flat substrate and a cover spaced therefrom. A first display unit is formed on the inner surface of the substrate while a second display unit is formed on the inner surface of the cover. Each of the first and second display units comprises electrodes arranged in a pattern to be displayed and phosphor films coated on the electrodes. The electrodes of the second display unit are made of transparent material. Where the electrodes of respective display units are selectively energized the phosphor films on the selected electrodes are caused to fluoresce by thermal electrons generated by a cathode electrode thus displaying a desired pattern.
