The text book of Microbiology as taught in different courses in various universities. It has been divided in five sections. The students of microbiology at present are required to consult a large number of books to grapple with the subject and, therefore, the form and details of this book have been given in order to give them basic understanding of the subject.Sections I deals with the history of microbiology, taxonomy, morphology and reproduction of micro-organisms, wherein, a brief account of eukaryotic microorganism is also discussed. Section II covers physiology wherein, a basic account of biochemistry and details of enzyme and metabolic processes in microorganisms is included. Further, certain techniques namely, ELISA and SDGC are also described. Section III deals with microbial genetics. Chapter 14 of this section starts with the basic terms used in genetics & description of nucleic acid. Besides microbial genetics transposable elements and transposition have been given. It also covers molecular biolo. Section IV deals with Applied Microbiology. Human and Plant Diseases have been covered. Detailed account of Immunology, Soil Microbiology, and Indus-trial Microbiology has been included. Geomicrobiology has been treated specially in a chapter separately devoted to it. Section V covers techniques wherein, various types of microscopy, instrumentation and cultural techniques are given. The students of microbiology at present are required to consult a large number of books to grapple with the subject and, therefore, the form and details of this book have been given in order to give them basic understanding of the subject.