CHARGED PARTICLE BEAM DEVICE PROVIDED WITH ION PUMP

摘要

In this charged particle beam device provided with an ion pump, low-frequency noise of the power source of the ion pump is sufficiently reduced to enable accurate measurement of a degree of vacuum. A drive power source unit (1) of an ion pump (2) is configured to comprise: high-voltage power source circuit units (101-112) that operate the ion pump (2); a load current detecting circuit unit (130) that detects load current applied to the ion pump (2); and a canceller circuit unit (140) that reduces low-frequency noise applied to the load current detecting circuit unit (130).