Lorentz Scanning Electron/Ion Microscopy: Observation and measurement methods for spatial electromagnetic fields were developed by using scanning electron/ion microscopes, in which a cross-grating was installed below the specimen. The specimens were observed under the infocus condition and the grating was simultaneously observed under the defocus condition. Projected electromagnetic fields around the specimen were reconstructed from the distorted cross-grating images in the similar way done by electron holography. The developed methods can be used in low and middle magnification and resolution ranges and are applicable to study their dynamics. Furthermore, these methods can be realizable in any electron/ion beam instruments because they are based on deflections due to Lorentz force for charged particle beams. Microscopy 71: 93–97.