This text is a systematic presentation of experimental measurements of the electron-phonon interaction in clean metals, obtained using the method of microcontact spectroscopy. Detailed micro-contact spectra (plots of the second derivative of the current-voltage characteristics of point micro-contacts, measured at low temperatures) are presented for 31 metals. These can be used in the calculation of thermodynamic and kinetic properties of metallic systems (electrical conduction, thermoconductivity, thermal expansion, etc.) as well as for verification of microscopic theories of metals. The book is intended for use by scientific researchers and graduate students working in the areas of solid state physics, low temperature physics, spectroscopy and the physics of metals.