To provide an image forming device that has small luminance irregularity due to aging by performing sealing easy to carry out in the atmosphere in a manufacturing process of an envelope to maintain vacuum, providing a getter manufacturing method that does not deteriorate the adsorbing capability of a nonvolatile getter, and maintaining the degree of vacuum.

In this manufacturing method of an image forming device, an organic metal compound containing a metal capable of serving as a getter material 99 is introduced, in a vapor phase, into an envelope 97 composed by sealing a rear plate 91 holding electron sources 74 and a face plate 96 holding an image forming member (phosphor) 94 interposing an outside frame 92 in the atmosphere, and thereafter, only a metal film 99 to serve as the getter material is formed in the envelope by removing organic ingredients.