A consistent electronic theory of adhesion is developed relating to the contact of bodies of different nature.The strength (as well as energy) of adhesion is calculated for the contact of crystal bodies (semiconductors, metals) as well as for the contact of amorphous bodies whose surface is saturated by donor and acceptor functional groups. The theory developed allows us to calculate the electrostatic component, when certain (experimentally determined) physiochemical characteristics of studied objects are known. The theory also determines the temperature dependence of the adhesion strength. The main inference is that cases of electrostatic component reading values of the order of 108−109(dyn/cm2) are fairly realistic. There follows from the theory the role of surface conditions as the chief factor of high adhesion. The theory suggests the ways for conditioning the adhesion via chemical modification of the surfaces (sometimes also of the bulk) of contacting bodies, and indicates which characteristics of solid bodies are to be studied when investigating the adhesion.