This volume is the first international collection of the best physics problems (both theoretical and experimental) given at the national physics competitions for high school students in different countries. The book introduces the short history of the International Physics Olympiad, the Statutes, the Syllabus, the statistical data including complete list of winners and a collection of national reports. Each of the national report will contains -- as a main part -- the best theoretical and experimental problems (with complete solutions) given at the national competition or at the training of the team before the international competition. Taking into account that at present the International Physics Olympiad involves about 35 countries, we are sure that the book will be interesting for everybody involved with physics education not only with the physics olympiads.