The book is based on the lecture course "Function spaces," which the author gave for more than 10 years in the People's Friendship University of Russia (Moscow). The idea to write this book was proposed by Professors H. Triebel and H.-J. SchmeiBer in May-June 1993, when the author gave a short lecture course for post-graduate students in the Friedrich-Schiller University Jena. The initial plan to write a short book for post-graduate students was trans formed to wider aims after the work on the book had started. Finally, the book is intended both for graduate and post-graduate students and for...