Charged particle beam apparatus

A charged particle beam apparatus comprising:

• a charged particle optical column that scans a sample with a primary charged particle beam;
• a detector that detects reflected electrons or secondary electrons obtained by the scanning;
• a vacuum pump;
• a housing portion in which the charged particle optical column is supported with respect to an apparatus installation plane, an interior of the housing portion being evacuated to a vacuum by the vacuum pump;
• and
• an attachment that can stores the sample therein with a pressure in the attachment being maintained higher than a pressure in the housing portion,
• wherein the attachment holds a thin film that allows the primary charged particle beam to penetrate or pass through an interior of the attachment,
• the attachment is vacuum-sealed to and fixed to a sidewall face or an inner wall face of the housing portion or to the charged particle optical column, and
• the attachment has an open face that allows the sample stored in the interior of the attachment to be replaced while the interior of the housing portion is maintained in a vacuum state.

An observation method for irradiating a sample maintained in an atmospheric pressure state with a charged particle beam emitted from a charged particle optical column whose interior is evacuated to a vacuum, via a thin film, and detecting resulting secondary charged particles to acquire an image of an irradiation position of the sample with the charged particle beam, the method comprising:

• causing the charged particle beam to pass through a first space that is formed by a housing that supports the charged particle optical column with respect to an apparatus installation plane;
• storing the sample in an attachment that is inserted into the first space from a side face of the first space, a pressure in the attachment being maintained higher than a pressure in the charged particle optical column, wherein the sample is stored through an open face of the attachment while an interior of the housing is maintained in a vacuum state;
• and
• irradiating the sample in the attachment with the charged particle beam via the thin film.