This fluorescent display tube includes an anode and a plurality of filament-shaped cathodes both provided in an envelope, a support as one of a pair of support bodies which support the cathodes is electrically divided for each of the cathodes and at the time of driving, and a cathode driving IC gives pulse voltages to the cathodes at different timing. Since the voltages are applied to the arranged cathodes sequentially, current flowing through the cathode driving IC can be small as compared with a case where voltages are simultaneously applied to a plurality of cathodes. Heat generation of the cathode driving IC is suppressed, and costs required for the cathode driving IC are reduced.