The objective of the present invention is to provide a charged particle beam device such that a tip part can be effectually maintained in a clean state, while the frequency of valve body replacements is also reduced. To achieve the objective, a charged particle beam device is offered, comprising: a partition that is positioned between a charged particle source-side vacuum space and a specimen stage-side vacuum space, said partition further comprising an opening for a charged particle beam to pass through; a driver mechanism that moves a shutter member between a first location within the optical axis of the charged particle beam and a second location outside the optical axis of the charged particle beam; and a control device that controls the driver mechanism. The first location is a location wherein the shutter member is distanced from the partition, and the control device carries out a control that opens a valve between the specimen chamber and the exchange chamber when the shutter member is in a state of being located in the first location.