Graduate students entering the field and high-energy astrophysicists will find this an accessible cosmic-ray manual, Easy to read for the general astronomer, the first part describes the standard model of cosmic rays based on our understanding of modern particle physics. The acceleration scenario is presented in some detail in supernovae explosions as well as in the passage of cosmic rays through the Galaxy. Experimental data in the atmosphere as well as underground are compared with theoretical models. The second part is devoted to contemporary cosmic ray research like the analysis of shower phenomena, the end of the cosmic spectrum and high-energy neutrino astronomy.