1. Introduction.- 2. Core Levels and Final States.- 3. Charge-Excitation Final States: Satellites.- 4. Continuous Satellites and Plasmon Satellites: XPS Photoemission in Nearly Free Electron Systems.- 5. Valence Orbitals in Simple Molecules and Insulating Solids.- 6. Photoemission of Valence Electrons from Metallic Solids in the One-Electron Approximation.- 7. Bandstructure and Angular-Resolved Photoemission Spectra.- 8. Surface States, Surface Effects.- 9. Inverse Photoemission Spectroscopy.- 10. Spin-Polarized Photoemission.- 11. Photoelectron Diffraction.- A.1 Table of Binding Energies.- A.2 Surface and Bulk Brillouin Zones of the Three Low-Index Faces of a Face-Centered Cubic (fcc) Crystal Face.- A.3 Compilation of Work Functions.- References.