"Introduction to Astrochemistry" is a comprehensive textbook that covers the fundamental principles of astrochemistry, an interdisciplinary field that combines astronomy, physics, and chemistry. The author, Satoshi Yamamoto, places special emphasis on the physical and chemical foundations that are crucial for understanding the chemical processes in various astrophysical environments. The book addresses topics such as diffuse clouds, dense stationary molecular clouds, star-forming regions, and protoplanetary disks. Additionally, it provides a brief introduction to molecular spectroscopy and observational techniques. This content enables astronomers to gain a thorough understanding of how interstellar matter evolves and is transformed into stars and planets, ultimately relating to the formation of the solar system. The book is also highly beneficial for physical chemists interested in exotic chemical processes under extreme physical conditions. It is aimed at all researchers starting at the graduate level.