The book deals with yantra pooja, design of yantras, the mantras being used for worshiping the yantra, energising (praan prathishtha) the yantra and other usages of the yantras. This book is the first part of work on tantra, mantra and yantra. The contents of this book are purely based on old Sanskrit classics. A detailed method of worshiping the yantras is given in the book which would be beneficial for the readers. The book contains colored pictures of the most popular yantras. Detailed diagrams with clear pictures, mantras of each yantra are also given.