To provide a panel with good discharge characteristics and stability and long life by strengthening getter action and increasing absorption ability of impurity gas exhausted in a discharge space at saving and working time of the panel.

As a getter material, a material having activation temperature higher than the maximum temperature of thermal process for making a panel vessel is used. Or, one having activation temperature lower than the maximum temperature of thermal process for making a panel vessel is used as a getter material, in which case, it is cooled till the activation time. Since the getter material is then activated at time when enough degree of vacuum is obtained, impurity gas absorption effect after a tip-off is not damaged, making penalization possible. As a result, vacuum degree reliability is improved after the tip-off.