The objective of the present invention is to maintain the surrounding of a sample at atmospheric pressure and efficiently detect secondary electrons. In a sample chamber of a charged particle device, a sample holder (4) has: a gas introduction pipe and a gas evacuation pipe for controlling the vicinity of a sample (20) to be an atmospheric pressure environment; a charged particle passage hole (18) and a micro-orifice (18) enabling detection of secondary electrons (15) emitted from the sample (20), co-located above the sample (20); and a charged particle passage hole (19) with a hole diameter larger than the micro-orifice (18) above the sample (20) so as to be capable of actively evacuating gas during gas introduction.