Shearography, one of the most up-to-date scientific and technological achievements, is a powerful measurement method capable of measuring micro-strains, stress distributions, strain distributions, etc. with high accuracy, and has been studied worldwide. Especially with the rapid development of computers and solid-state imaging sensors, shearography is becoming a more important tool in the measurement of microstrain. And shearography is widely used worldwide today due to its simplicity of optical systems, low measurement environmental requirements and the advantages of using inexpensive semiconductor lasers.This book describes the principles of shearography in industrial applications.Non-destructive testing is a term that means the technique of detecting internal defects without damaging the object being tested, and its requirements, including the aerospace and precision industries, are increasing with each passing day. Shearography is a powerful tool for non-destructive testing as a method for measuring micro-strains with high accuracy. Starting from this starting point, this book is written for the purpose of giving the Knowledge of the principle of shearography and its applications.