The negative effects of specimen contamination in EM analyses (especially TEM analysis) can be reduced or even eliminated by so-called electron beam flooding or beam shower. In TEM, the flooding is normally done at low magnification with a large electron flux. In this way, the contaminants (mainly hydrocarbons) on the TEM specimen can be polymerized in the form of a uniform fixed layer or can be cracked, and thus the contaminants will neither move to nor accumulate in the electron-analyzing area.