Preface, I. Banach Algebras, 1. Review on Functional Analysis, 2. Banach Algebras and the Invertible Group, 3. The Spectrum, 4. Multiplicative Linear Functionals, 5. The Gelfand Transform and Applications, 6. Examples of Maximal Ideal Spaces, 7. Non-Unital Banach Algebras, II. C*-Algebras, 8. C*-Algebras, 9. Commutative C*-Algebras, 10. The Spectral Theorem and Applications, 11. Further Applications, 12. Polar Decomposition, 13. Positive Linear Functionals and States, 14. The GNS Construction, 15. Non-Unital C*-Algebras, III. Von Neumann Algebras, 16. Strong- and Weak-Operator Topologies, 17. Existence of Projections, 18. The Double Commutant Theorem, 19. The Kaplansky Density Theorem, 20. The Borel Functional Calculus, 21. L degrees degrees as a von Neumann Algebra, 22. Abelian von Neumann Algebras, 23. The -Functional Calculus, 24. Equivalence of Projections, 25. A Partial Ordering, 26. Type Decomposition, Bibliography, Index