Superconductor materials are able to conduct current without any energy losses. These materials have remarkable and highly desirable feature for applications. Superconductivity is a quantum mechanical phenomenon and we apply quantum field theory to explain this phenomenon. Readers with some prior knowledge of condensed matter physics will find it very interesting. This monograph is intended to show the mechanism of superconductivity in A3C60(A=K, Rb and Cs) superconductors. The first part of this monograph shows exclusive excitonic mechanism of superconductivity in A3C60(A=K, Rb and Cs)...