Charged particle beam device

As a device for correcting positive spherical aberration of an electromagnetic lens for a charged particle beam, a spherical aberration correction device combining a hole electrode and a ring electrode is known. In this spherical aberration correction device, when a voltage is applied between the hole electrode and the ring electrode, the focus of the charged particle beam device changes due to the convex lens effect generated in the hole electrode. Therefore, in a charged particle beam device including a charged particle beam source which generates a charged particle beam, a charged particle beam aperture having a ring shape, and a charged particle beam aperture power supply which applies a voltage to the charged particle beam aperture, the charged particle beam aperture power supply is configured to apply, to the charged particle beam aperture, a voltage having a polarity opposite to a polarity of charges of the charged particle beam.