An objective of the present invention is to provide a charged particle beam device capable of estimating a lifetime of a filament of a charged particle beam source with a cheap and simple circuit configuration. The charged particle beam device according to the present invention includes a boosting circuit that boosts a voltage to be supplied to a filament and estimates a remaining duration of the filament using a measured value of a current flowing on a low-voltage side of the boosting circuit (see FIG. 3).