This book is an introduction to the study of Islamic finance. The author's reasoning focuses mainly on the presentation of the financial instruments in use. This is done by clarifying the historical framework and setting out the fundamental principles summarised in the 3P rule (Share-Lose-Profit). Emphasis is placed on traditional instruments (Murabaha, Al-Salam, Al-Ijara and Al-Istisnaa) and participative instruments (Musharaka and Mudharaba) to give readers an overview of the mechanisms for allocating funds to investment projects.