Electron gun and electron beam application device

An electron beam application device, comprising:

• an electron optical system including an electron gun and configured to irradiate a sample with a pulsed electron beam emitted from the electron gun;
• a detector configured to detect, by irradiating the sample with the pulsed electron beam, electrons transmitted through the sample or electrons emitted by interaction with the sample;
• and
• a control unit configured to control an irradiation condition of the pulsed electron beam emitted from the electron optical system to the sample, wherein
• the electron gun includes:
• a photocathode including a substrate and a photoelectric film formed on the substrate;
• a light source configured to emit a pulsed excitation light;
• a condenser lens facing the substrate of the photocathode and configured to condense the pulsed excitation light toward the photocathode;
• and
• a first anode electrode and a second anode electrode disposed facing the photoelectric film of the photocathode,
• the first anode electrode is disposed between the photocathode and the second anode electrode, a surface of the first anode electrode facing the second anode electrode has a recessed shape, and a surface of the second anode electrode facing the first anode electrode has a protruding shape, and
• the control unit optimizes the irradiation condition of the pulsed electron beam emitted from the electron optical system to the sample according to a parameter of the electron gun under a predetermined pulse condition set for the electron gun.