Method for adjusting charged particle beam device and adjusting beam aperture based on a selected emission condition and charged particle beam device for same

The present invention relates to enabling a versatile charged particle beam device, which is used for a wide range of kinds of samples to be observed and has parameters of emission conditions of a primary charged particle beam that is difficult to be registered in advance, to be operated easily and accurately even by a less-experienced operator and to obtain high-resolution images. A charged particle beam device according to the present invention includes, for example: a charged particle source, a focusing lens for a primary charged particle beam emitted from the charged particle source, an objective lens for focusing the primary charged particle beam, a movable objective aperture having multiple objective apertures disposed on a side of the charged particle source with respect to the objective lens, a detector of a secondary signal from the sample resulting from emission of the primary charged particle beam, a display unit configured to process and display a detected secondary signal, and a storage unit configured to store multiple emission conditions of the primary particle beam. The operation controller makes one emission condition be selected, determines whether or not the objective aperture is suitable for the selected emission condition, displays that the objective aperture is unsuitable when the objective aperture is unsuitable, and preadjusts the primary charged particle beam according to the selected emission condition and stores the preadjustment result as parameters for the emission conditions when the objective aperture is suitable.