This book aims to introduce the Circular Economy to companies, in order to understand its origin, principles and benefits. The book presents a methodology to approach the Circular Economy in a systematic way. The guide is structured in four chapters that show the steps to help organizations on their way to the Circular Economy. The chapters are: 01. Transition to the Circular Economy, 02. Fields of Action in the Circular Economy, 03. Implementation methodology, 04. Tools for developing the Circular Economy. The methodology follows the improvement cycle, based on 1. Diagnosis, 2. Opportunity analysis, 3. Implementation plan, 4. Evaluation and feedback. The last chapter also presents a set of tools to help companies in their way to the Circular Economy