Patent attributes
In order to improve a yield of light generated by a collision between secondary electrons and gas molecules, the invention provides a charged particle beam device including: a charged particle beam source configured to irradiate a sample with a charged particle beam; a sample chamber configured to hold the sample and a gas molecule; a positive electrode configured to form an electric field that accelerates a secondary electron emitted from the sample; a photodetector configured to detect light generated by a collision between the accelerated secondary electron and the gas molecule; and a light condensing unit disposed between the sample and the photodetector, having a light emitting space in which the light is generated, and configured to condense the light generated in the light emitting space on a photodetector side.