Abstract: A method and apparatus for preparing a specimen adapted for electron microscopy comprises an evacuated specimen-processing chamber. A specimen having a surface to be processed is placed inside the processing chamber A beam-blocking member is placed close to the processed surface so as to block a part of an etching beam A first etching step is performed by directing the beam at the specimen via the blocking member. Then, the specimen and the blocking member are moved relative to each other. Finally, a second etching step is performed by directing the beam at the specimen via the blocking member. As a result, the specimen becomes a thin film and it can be observed with the electron microscope.