Inspection device and inspection method

An inspection device comprising:

• an emitter configured to emit first charging particles;
• a deflector configured to deflect the first charging particles to scan a surface of a target object with the first charging particles;
• a detector configured to detect second charging particles generated from the surface of the target object based on receiving the first charging particles;
• an image generator configured to generate an image of the surface of the target object based on a detection result of the second charging particles by the detector;
• a controller configured to control a scan direction of the first charging particles;
• and
• a processing circuit configured to:
• detect normal directions to a contour of an uneven portion on the surface of the target object in a first image obtained by scanning the surface of the target object with the first charging particles in a first scan direction for a plurality of unit regions of the first image,
• calculate a frequency of a first angle formed by a reference axis of the first image and a normal direction of each of the plurality of unit regions,
• determine the normal direction corresponding to a most frequent value of the first angle among the normal directions as a second scan direction, and
• calculate a height of the uneven portion based on a second image obtained by scanning the surface of the target object with the first charging particles in the second scan direction.