PURPOSE: To facilitate formation of LaB6 electrode by printing LaB6 paste onto the underlying electrode and burning thereafter activating through high current gas discharge.

CONSTITUTION: LaB6 paste where 0.2W0.4wt% of alkali glass fine powder is mixed with 1wt% of LaB6 powder is lamination printed onto Ni underlying electrode 10 then burnt under dry air to form LaB6 layer 11. Upon completion of frit seal, thermal exhaust, encapsulation of required gas and final encapsulation, predetermined voltage is applied between the anode and Ni underlying electrode 10 to perform activation through high current gas discharge. Consequently, glass will never exist on the surface of the LaB6 layer 11 to expose LaB6 itself while burning will occur between LaB6 particles resulting in formation of LaB6 cathode 12 on Ni underlying electrode 10.