Scanning transmission electron microscope and scanning transmission electron microscopy

An electron microscope, comprising:

• an electron gun for generating a primary electron beam, and a control unit for said electron gun,
• an irradiation-system lens for converging said primary electron beam to irradiate said converged primary electron beam to a specimen, and a control unit for said irradiation-system lens,
• a scanning coil for scanning said converged primary electron beam on said specimen, and a control unit for said scanning coil,
• a specimen stage for holding said specimen, and a control unit for said specimen stage,
• an electron detector for detecting an electron beam which has transmitted said specimen, and a control unit for said electron detector, and
• an image formation unit for forming an image by synchronizing an output value from said electron detector with a control value for said scanning coil, and a control unit for said image formation unit, wherein,
• said electron microscope further comprises:
• a correction unit for correcting a displacement of said transmitted electron beam relative to said electron detector, said displacement of said transmitted electron beam being caused by a displacement of said primary electron beam relative to said specimen,
• a measurement unit for measuring said displacement of said transmitted electron beam,
• an analysis unit for determining a correction-unit control value needed for correcting said displacement of said transmitted electron beam,
• a memory for recording said correction-unit control value, and
• a control unit for outputting said correction-unit control value to said correction unit in synchronization with said control over said scanning coil, said correction-unit control value being recorded in said memory.