The Qur'an is a divine message presented to the consciousness of humanity within the possibilities and limits of the Arabic language. The elements and basic features of the language in which the Qur'an was revealed certainly have an important place in understanding and interpreting this divine message. One of the basic elements that shapes meaning in the Arabic language is ma. ani letters, which are defined as particle. In this context, the main purpose of this study is to present different meanings of particle illa, which is one of ma. ani letters and to identify the effects of these different usages on the Qur'an interpretation. This identification will provide richness of interpretation of verses which include illa. For this purpose, the meaning field of the particle illa in the Arabic language will be explored; then in sub-headings how this particle was interpreted in the Qur'an will be examined. According to this, it is found that the particle illa in the Arabic language is used in very different meanings, and that some verses have been interpreted by taking these different meanings into consideration. This result shows that the particle illa should not be interpreted as a particle of exception only, and that this particle's other meanings and expressions should be taken into account.