Classics of Science write that the electron beam falling onto a nickel crystal gives a diffraction pattern which can be explained only on the basis of wave theory. And further that the wave nature of electron is established as firmly as corpuscular. The author claims that the interpretation of Davisson - Germer experimental results was wrong. These experiments proved only energy stationary states for nickel atom but nothing else! From this it follows that there is no evidence of the existence of de Broglie waves. A photon has no invariant mass during the propagation in space so it has wave properties; when interacting with a substance a photon exhibits the properties of a particle that has a momentum. Electron is a particle that has an invariant mass and moving at any speed remains a particle, and it does not exhibit any wave properties. But just like other elementary particles - neutrons, protons, α-particles and other ions during the interaction with the substance it is subjected to scattering, a change of its original direction, i.e. is subjected to diffraction as well as waves. A similar picture resulting from the two different processes still does not prove the wave processes in both cases. Photons of electromagnetic waves and electrons, as well as other particles with invariant mass belong to two different forms of matter, and we have no right to equalize them.