The book "Manuscript Treasures of Matenadaran" tells about ancient and medieval Armenian manuscripts stored in the State Matenadaran and are unique in world literature. It gives a brief history of Matenadaran, from the fifth century to the present, and gives general information about "grichas" (scribes of manuscripts) and manuscript schools. In separate chapters, the most valuable manuscripts of Matenadaran are presented in certain branches of science - history, law, literature, geography, medicine, exact sciences, etc. The final chapter talks about the storage and study of the primary sources of Matenadaran, as well as the great care that is currently manifested about Matenadaran, this richest treasury of the cultural heritage of the Armenian people. The book contains over 20 photographs of the oldest manuscripts.