AIR-TIGHT DEVICE, ELECTRON BEAM DEVICE, AND IMAGE FORMING DEVICE

摘要

An air-tight device having an inside pressure lower than an outside pressure, comprising a plurality of plate-shaped spacers (15) which suppress the deformation of an inside form and getter materials (9) for increasing the degree of vacuum each of which is located in a space between the two plate-shaped spacers (15), whereby gas produced inside an envelope is adsorbed immediately by the getter materials (9) and the degree of vacuum inside the envelope can be maintained satisfactorily.