Book excerpt: Laser Photoionization Spectroscopy discusses the features and the development of photoionization technique. This book explores the progress in the application of lasers, which improve the characteristics of spectroscopic methods. Organized into 12 chapters, this book starts with an overview of the fundamentals of the method for atoms and molecules. This text then examines the photoionization spectroscopy, which is based on the laser resonant excitation of particles into high-lying quantum states that are easy to detect by ionization. Other chapters explain the various basic schemes of multistep excitation, which can be used for resonance photoionization of molecules. This book discusses as well the different applications of the resonance photoionization technique in atomic and molecular spectroscopy. The final chapter considers the two well-known types of microscopy, namely, wave and corpuscular. This book is a valuable resource for chemists, physicists, analysts, and geochemists who are interested in laser spectroscopy techniques to solve nontrivial problems.