An electron microscope is offered that is capable of achieving noise cancellation which results in a low level of noise and which can be implemented at high speed. An electron microscope (1) associated with the present invention includes: an electron beam source (11) for producing an electron beam; a noise detector (4) for detecting a part of the beam to thereby produce a beam detection signal and dividing a dividend by the beam detection signal; at least one image signal detector (6) for detecting an image signal obtained by making the beam impinge on a sample (A); and an arithmetic section (60) for performing a multiplication between an output signal of the image signal detector (6) and an output signal of the noise detector (4).