Specimen machining device and specimen machining method

A specimen machining device for machining a specimen by irradiating the specimen with an ion beam, the specimen machining device comprising:

• an ion source for irradiating the specimen with the ion beam;
• a shielding member disposed on the specimen to block the ion beam;
• a specimen stage for holding the specimen;
• a camera for photographing the specimen;
• a coaxial illumination device for irradiating the specimen with illumination light along an optical axis of the camera;
• a transmission illumination device for transmissively illuminating the specimen;
• and
• a processing unit for determining whether to terminate the machining based on an image photographed by the camera,
• the processing unit configured to perform processing for:
• acquiring information indicating a target machined width;
• acquiring the image;
• extracting from the image two inclined surfaces formed by the machining based on a dark appearance of the two inclined surfaces in the image due to the coaxial illumination;
• measuring a machined width on the acquired image, the machined width being a distance in a direction perpendicular to both the ion beam and the illumination light, between the two inclined surfaces;
• and
• terminating the machining when the measured machined width equals or exceeds the target machined width,
• wherein each of the inclined surfaces is formed in a boundary between a machined region of the specimen and an unmachined region of the specimen.