CHARGED PARTICLE BEAM DEVICE AND DETECTOR POSITION ADJUSTMENT METHOD FOR CHARGED PARTICLE BEAM DEVICE

By minimizing axial misalignment and changes in a decelerating field resulting from a structure between an objective lens and a sample in a charged particle beam device provided with a deceleration optical system, the present invention reduces adverse effects on an irradiation system and a detection system. This charged particle beam device comprises: an electron source 2; an objective lens 4 forfocusing a probe electron beam from the electron source on a sample 12; an accelerating electrode 3 that accelerates the probe electron beam; a first detector 6 provided within the accelerating electrode; a decelerating electrode 5 that forms a decelerating field for the probe electron beam in the interval between said decelerating electrode 5 and the accelerating electrode and that has an openingthrough which the probe electron beam passes; and a second detector 7 inserted between the decelerating electrode and the sample. The second detector comprises an opening section 9 that is larger than the opening in the decel