To provide a display tube not required to be heated up to a prescribed temperature at which glass is fused and requiring no heating furnace by sealing an exhaust hole provided on a glass sheet via anode connection with silicone to form an airtight container.

An exhaust hole 2 is communicated with an through opening 11a, a display tube 1 is mounted on a mount table 11, a fixing jig 18 is fitted to the mount table 11, and the display tube 1 is fixed to the mount table 11 by the exciting force of an elastic pressing body 18a. A switch valve 13A is opened, a vacuum pump is operated to evacuate the display tube 1, and the switch valve 13A is closed after the display tube 1 is made vacuum. A switch valve 13B is opened, a specific gas is introduced into the display tube 1 from a guide port 12b, and the switch valve 13B is closed. The prescribed voltage is applied to a glass substrate 2 and a lift lever 15 by a power supply 20, and an exhaust port 2a is sealed by a cover member 5 via anode connection.