The church facade of the Certosa of Pavia is examined from different point of views: history, ancient restoration work, materials, decay, environment. The book is divided into seven parts: history of construction; history of the conservation works (1760-1980), including the transcription of a great number of original documents; stone materials and their state of preservation; study of the causes of stone decay presented with environmental data; examination of red stains on the Carrara marble; characteristics of the mortars employed for sealing and repointing; ancient treatments of stone surfaces (with the presence of calcium oxalates).