IntelliJ IDEA (hereafter referred as IntelliJ) is one of the most powerful and popular Integrated Development Environments (IDE) for Java. It was developed and is maintained by JetBrains, and is available in community and ultimate edition. This feature-rich IDE enables rapid development and helps in improving code quality. This tutorial starts with a basic introduction and slowly dives deep into the advanced features. The tutorial is divided into 2 parts: beginners can start from the first 4 chapters. Others can skip over directly to Chapter-5.