Patent ID: 8546770

Claim:
A charged particle beam device comprising: an ionic liquid holding member having an opening; an ionic liquid supplying unit for filling an ionic liquid into the opening; an observation unit for observing an adhesion state of the ionic liquid; and a charged particle beam generating unit for radiating charged particle beams, wherein a thickness of a droplet of the ionic liquid to be filled in the opening can be adjusted for observing a sample in a state where the sample is floating in the ionic liquid by being dispersed in the ionic liquid or on a surface of the ionic liquid, wherein the ionic liquid supplying unit is a mechanical probe which includes an ionic liquid portioning part for portioning a fraction of the ionic liquid from a pallet part storing the ionic liquid and for filling the fraction into the opening; an arm part for moving the ionic liquid portioning part; and a support part for supporting the arm part, and wherein the ionic liquid portioning part is adapted to be capable of mainly filling the ionic liquid into the opening.