Recently, foreign languages have started to be introduced to children at an earlier age with the influence of globalization as well as the continuous encouragement of early foreign language learning in Europe by the European Commission. However, language teachers around Europe are reported to have difficulties dealing with children because they are generally educated to teach adults or they are generalists who have not received special education on language learning. As children have different characteristics from those of adults, they need special classroom methods and techniques geared to their special needs. Therefore, having been inadequately prepared to teach languages to particularly young learners, teachers have problems while working with children and their teaching practices are often lacking in innovative approaches, variation and challenges, and interesting and motivating materials and activities. This situation indicates serious problems regarding the knowledge base and practices of teachers with regard to teaching children, which needs to be addressed. Therefore, in this project, we aim to design an INSET program based on an innovative flipped approach to learning, in which first, a web-based INSET program with 10 modules help language teachers become familiar with recent theories and pedagogical approaches concerning teaching foreign languages to young learners. Second, teachers implement and test these innovative approaches in their own classes under the supervision of the trainers and learn by doing. Third, based on their own classroom needs, the teachers develop their practical solutions and classroom activities considering the introduced theories and approaches through collaboration with peer teachers and teacher trainers. And finally, at the end, in addition to the theoretical and pedagogical INSET content, the tested and approved best classroom practices will be selected and uploaded to the web portal of the INSET program, which will be openly disseminated for use of all pre-service and in-service language teachers of young learners in Europe. Unlike common top-down one-shot in-service courses, our Web-based INSET program is longer and flexible in terms of time, it is designed based on teachers' needs which will be determined through a needs analysis survey, it puts teachers' needs at the center, values their ideas, adopts a bottom-up approach, allows collaboration among teacher trainers and teachers as well as teachers across countries to form the content of the course, and includes a school-based follow up component to support for teachers, which is generally neglected in mainstream INSETs. This program also evenly blends the theory and practice for teaching languages to young learners by bringing researchers/teacher trainers and classroom language teachers together at all stages of designing and implementation of the program. The Web-based INSET program designed aims to remedy the problems caused by inadequate professional preparedness of teachers for early language teaching by introducing the recent cutting edge theoretical and pedagogical knowledge, new and innovative ideas for methods, teaching techniques, activities, best classroom practices, and resources to both pre-service and in-service language teachers of young learners in Europe. This Web-based INSET program aims to improve teacher quality and professional profile of primary-level language teachers across Europe, and to serve as a good model for other INSET program developers and policy makers across Europe. The INSET program is likely to contribute to the realization of multilingualism, which is an important goal of the European Council because although our INSET website will be prepared in English, all the methodologies, pedagogical suggestions, and activities included will be valid and completely adaptable for teaching/learning other various languages for young learners. And finally, the Web-based INSET program aims to contribute young learners in Europe to learn languages more effectively with the help of better prepared teachers for their age specific needs.