The subject treats electronic structure of crystalline solid matter. The subject starts by the relation between crystal symmetry, its electronic structure and its physical properties. It further introduces numerical techniques providing calculations of electronics structure from first principles (so called ab-initio), together with discussion of needed approximations. Once electronic structure is known, many physical properties may be calculated, which is demonstrated on example on electron and heat conductivity, as well as optical properties of solids. Finally, we discuss influence of spin on electronic structure (i.e. magnetism) and short introduction into quasi-particles and collective excitations.