This study aims to preserve and save the scientific treasures of the scholars of the archipelago in the form of coastal ancient manuscripts at the Jami' Lasem Mosque Library, Rembang. The condition of the ancient manuscripts is now damaged, weathered due to age. If not saved immediately, the contents of the manuscript will be damaged and unreadable. Though the contents are very useful for today's life. The effort that needs to be done is to digitize the manuscript, while the original manuscript can be preserved by means of preservation. Digitization is not only to preserve the contents of the manuscript but also to maintain health and the environment. We managed to digitize four of the 14 manuscripts in the Lasem Mosque library. The potential of ancient manuscripts in Lasem still needs to be traced again considering that Lasem is an old city where an old pesantren was founded in Java.