This book presents a detailed analysis of the processes of  internal damage and healing of damage in high-temperature creep-fatigue. This analysis is based on experimental results and a three-dimensional visualization and simulation method. It focuses on inner cracking type fracture, which is essential to consider for creep-fatigue in actual equipment and structures used at high temperatures for long periods of time. In this book, systematic studies of the fracture are presented by introducing three-dimensional simulation and visualization methods. This book is for designers and researchers in industry specializing in strength of materials at high temperatures. It is also for a postgraduate or higher academic audience specializing in mechanical engineering and materials science engineering. In reading the book it is expected that readers will acquire knowledge of evaluation techniques for high-temperature creep-fatigue damage. In addition, this book allows readers toimprove the accuracy of damage evaluation, design materials for longer lifetimes, and apply the described techniques to other materials.