The International Conference on Electron and Photon Impact Ionization and related Topics was held in July 2004 in Louvain-la-Neuve, Belgium. It belongs to a series including ICPEAC Satellites and a number of Euroconferences which have been held since 1989. The meeting brought together about 80 scientists, from 19 different countries. The scientific programme included 22 invited talks and 54 poster presentations. These proceedings provide an overview of the latest advances in the field of ionization by electron and photon impact. This conference covers a broad range of current topics such as multi-particle coincidence studies: in particular, (e,2e) and (e,3e) processes; photoionization with or without excitation; and multiphoton single and double ionization. The book contains 18 refereed contributions on recent experimental, theoretical and computational work on correlated processes involving a wide range of targets (atoms, molecules, clusters and surfaces). Three review talks have been organized on the following topics: anisotropy and polarization in Auger-electron emission; multiple ionization of atoms in strong fields; and theoretical and practical aspects of photoionization with excitation. As a record of the conference, this book is an essential reference for researchers working in atomic, molecular, cluster and surface physics. Due to the broad range of applications, such proceedings should be of great interest to chemists and biologists.