Patent ID: 8686380

Claim:
A charged particle beam apparatus, comprising: a charged particle beam generator having a charged particle source; a charged particle optical system that enters charged particle beams emitted from the charged particle source on a sample; a vacuum evacuating means that evacuates the charged particle beam generator and the charged particle optical system; and a subsidiary vacuum pump that evacuates the charged particle beam generator, and wherein the charged particle source is configured of a field emission type charged particle source and the subsidiary vacuum pump is configured of a first non-evaporable getter pump comprising an alloy surface that extends orthogonally to a direction in which the charged particle beams are emitted from the field emission type charged particle source, wherein, the field emission type charged particle source is disposed to emit the charged particle beams in a gravity direction, wherein an electrode having an aperture through which the charged particle beams passes is provided immediately below the field emission type charged particle source, wherein the first non-evaporable getter pump is disposed around the aperture on the electrode surface, and wherein the electrode has a groove formed on a surface thereof, and the first non-evaporable getter pump is formed on a bottom of the groove.