Abstract: A large current electron beam is stably emitted from an electron gun of a charged particle beam device. The electron gun of the charged particle beam device includes: a SE tip 202; a suppressor 303 disposed rearward of a distal end of the SE tip; a cup-shaped extraction electrode 204 including a bottom surface and a cylindrical portion and enclosing the SE tip and the suppressor; and an insulator 208 holding the suppressor and the extraction electrode. A shield electrode 301 of a conductive metal having a cylindrical portion 302 is provided between the suppressor and the cylindrical portion of the extraction electrode. A voltage lower than a voltage of the SE tip is applied to the shield electrode.

Abstract: A chemical agent-spraying device is provided with a chemical agent tank and chemical agent-jetting parts that jet out a chemical agent supplied from the chemical agent tank. The chemical agent-jetting parts include a first chemical agent-jetting part that jets out the chemical agent onto the reverse surfaces of crop leaves as an area to which the chemical agent is to be jetted, and a second chemical agent-jetting part that jets out the chemical agent onto the obverse surfaces of crop leaves as an area to which the chemical agent is to be jetted.