1897 Discovery of electron (J.J. Thompson)
1924 Particle Wave theory (L. deBroglie)
1926 Electromagnetic lens (H. Busch)
1927 Electron Diffraction (Davisson & Germer)
1932 1st TEM (M. Knoll & E. Ruska)
1936 Demonstration of SEM theory (M. Knoll)
1938 1st SEM (M. von Ardenne)
1939 1st commercial TEM (B. von Borries & E.Ruska)
1942 Production of electrostatic lens SEM
1956 Production of electromagnetic lens SEM
1960 Improved SE detector (Everhart & Thornley)
Mid 1960’s 1st Commercial SEM (Cambridge Instruments Co Ltd)