CHARGED PARTICLE BEAM DEVICE PROVIDED WITH ION PUMP

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. Adrive 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). 在具备离子泵的带电粒子束装置中，能够使离子泵的电源的低频噪声充分地降低而对真空度高精度地进行计量。离子泵(2)的驱动电源部(1)构成为，具备：高压电源电路部(101-112)，其使离子泵(2)工作；负荷电流检测电路部(130)，其对向离子泵(2)施加的负荷电流进行检测；以及消除电路部(140)，其使施加于负荷电流检测电路部(130)的低频噪声降低。