In a simple and progressive way, this book explains the ideas and techniques of statistical mechanics. Most other books of the same subject tend to be dry and unappealing and undergraduates find themselves confused with the difficult maths presented. This is indeed a tricky subject toexplain and techniques doing so are often complicated. However this book starts with the laws of thermodynamics and simple ideas of quantum mechanics and the reader is led through progressively more complex problems with all the mathematical detail explained. This will be a much welcomed book byall physics and chemistry undergraduates studying the subject