An apparatus for allowing the opposite surfaces of a band-shaped or web-like material to be subjected to vacuum glow-discharging treatment includes a vacuum housing in which two rows of electrodes are arranged with the band-shaped material interposed therebetween, and an elongated annular hollow space serving as a coolant flow path is formed in each electrode. A coolant supplying pipe for supplying a coolant through the elongated annular hollow space and a coolant discharging pipe for discharging the coolant from the elongated annular hollow space are connected to the electrode. Stable electricity discharging treatment can be conducted for a long time without any occurrence of abnormal electricity discharging by preventing the temperature of each electrode from being excessively elevated.