| CPC H01J 37/21 (2013.01) [H01J 37/06 (2013.01); H01J 37/222 (2013.01); H01J 37/244 (2013.01); H01J 37/265 (2013.01); H01J 37/28 (2013.01); H01J 2237/216 (2013.01)] | 13 Claims | 

| 
               1. A charged particle beam device comprising: 
            an electron gun capable of emitting an electron beam; 
                an objective lens for focusing the electron beam; 
                a stage for installing a sample; 
                a detector capable of detecting secondary electrons or reflection electrons emitted from the sample as a signal when the sample is installed on the stage and the sample is irradiated with the electron beam at the time of analysis of the sample; 
                a control unit electrically connected to the electron gun, the objective lens, the stage, and the detector, and having an image processing control circuit capable of converting the signal detected by the detector into a photographed image; 
                a photographing function for automatically continuously photographing each of a plurality of photographing visual fields in the sample, which are analysis targets, as the photographed image at the time of analysis of the sample; and 
                an autofocus function for automatically focusing each of the plurality of photographing visual fields and automatically calculating focus values thereof at the time of analysis of the sample, wherein 
                each of the plurality of photographing visual fields is focused in a first focus value calculation visual field adjacent to the photographing visual field designated as a photographing target among the plurality of photographing visual fields, and 
                the focus value calculated in the first focus value calculation visual field is used for calculating the focus values of each of the plurality of photographing visual fields. 
               |