Patent ID: 8217363

Claim:
A scanning electron microscope that scans a specimen using an objective lens with a primary electron beam which is emitted from an electron gun to obtain a scan image of the specimen, the scanning electron microscope comprising: a plurality of circular symmetric magnetic field lenses disposed between the objective lens and the electron gun, one of the circular symmetric magnetic field lenses that is not closest to the objective lens among the plurality of circular symmetric magnetic field lenses forming a crossover point of the primary electron beam in a magnetic field that is formed by the circular symmetric magnetic field lens that is closest to the objective lens among the plurality of circular symmetric magnetic field lenses; and a detection unit to detect secondary particles that are generated from the specimen by irradiation of the primary electron beam, the detection unit being disposed between the circular symmetric magnetic field lens that is closest to the objective lens and the circular symmetric magnetic field lens that forms the crossover point of the primary electron beam.