Abstract: A d.c. gas-discharge display device has gas-discharge display panel including hot cathodes inserted in a thermal electron generating space, an insulating plate having holes as discharge-glow spaces and on one surface thereof grid electrodes with holes for penetration of thermal electrons and on another surface thereof anode electrodes, and gas, metallic vapor on a mixture thereof, which fills the space in the display panel and forms an envelope. A voltage generator supplies the cathodes with a potential to provide thermal electrons. A first pulse generator supplies the grid electrodes with a pulse having a pulse height higher than V.sub.ON and being biased by a d.c. voltage lower than V.sub.OFF.A second pulse generator supplies the anode electrodes with a positive pulse having a pulse height higher than the ionization voltage of the gas, metallic vapor or mixture and being biased by a d.c. voltage between ground level and the ionization voltage.