This book has been written for those whose interests bridge food processing and physicochemical aspects of radiation. It is not intended to be a comprehensive review of publications concerning foods and radiations. Instead, it is an attempt to familiarize the reader with pertinent knowledge of a unified, interdisciplinary concept of various electromagnetic radiations and corresponding effects on foods. Consideration was given to similarities and differ- ences between various segments of the electromagnetic spectrum. The broad approach of this book was considered to be crucial for cross-discipline comparisons. The reader is introduced to the electromagnetic spectrum in the Prologue and then the book follows the wavelengths, from short to long values. Chapter 1 deals with ionizing radiation: historical background, sources of radiation employed in food treatment, units of measurement, and fundamentals of radiation chemistry. A survey of potential applications of ionizing radiation in food technology is followed by a description of methods for radiation dosimetry. Safety and wholesomeness of irradiated foods, analytical methods for postirradiation dosimetry in foods, and consumer acceptance of food irradiation conclude this section. Chapter 2 intrudes into the next segment of the spectrum: ultra- violet-visible radiation. The general presentation of this electro- magnetic emission and illumination source enables the discussion of its effects on foods, including applications in food analysis.