A charged particle beam device includes: a plasma generation device attached to a sample chamber through a connecting member; a guide including a hollow portion configured to guide a plasma generated by the plasma generation device in a direction toward a stage; a first voltage source configured to apply a voltage to the stage; and a second voltage source configured to adjust the plasma generation device and the guide to a predetermined potential, in which the guide is disposed to avoid an opening of an objective lens through which a charged particle beam passes and to position a tip of the guide between the objective lens and the stage.