A redeposited material is removed so as to electrically observe a microelement without causing foreign matters or metal contamination. An FIB device (charged particle beam device) includes an FIB barrel which discharges the focused ion beam (charged particle beam), a stage which holds a sample (substrate), a microcurrent measuring device (current measuring unit) which measures a leakage current from the sample, and a timer (time measuring unit) which measures a time to emit the focused ion beam and a time to measure the leakage current. Further, the FIB device includes a system control unit (control unit) which synchronizes a time to emit the focused ion beam and a time to measure the leakage current by the microcurrent measuring device.