To carry out highly precise axis matching without dividing image data in an automatic axis matching method of a charged particle beam device and a charged particle beam device.

In a charged particle beam device irradiating a part of charged particle beams to a sample as a probe, a suitable observation magnification and an emitter tip potential change volume for correcting axial deviation of an objective lens are selected, displacing volume of a charged particle beam scanning image at the time of changing potential of an emitter tip to a charged particle beam scanning image at the time before changing that potential is calculated, the objective lens axial deviation is calculated from the calculated displacing volume, then, a feedback to correct the objective lens axial deviation to a deflector placed at a front of the objective lens is carried out.