Electric field emission device

An electric field emission device comprising:

• a vacuum vessel configured to include a vacuum chamber;
• an emitter that is positioned on one side in an axial direction of the vacuum chamber and includes an electron generation portion facing an other side in the axial direction of the vacuum chamber;
• a target that is positioned on the other side of the vacuum chamber and provided to face the emitter;
• a guard electrode that is a cylindrical body provided on an outer peripheral side of the emitter, is fixed to the vacuum vessel on the one side, and has an opening portion on the other side;
• a support configured to move the emitter in the axial direction on an inner side of the guard electrode;
• and
• an electric field shield body that is formed of a conductor connected to the guard electrode and is disposed on one side of an edge portion of the guard electrode, wherein
• the electric field shield body is disposed so as to partially overlap the opening portion on a projection plane in the axial direction, and is formed in a shape partitioning the opening portion into a plurality of areas.