Silk fibroin is a natural biomaterial that has the biocompatibility and other many advantages. But as a silk fibroin membrane thickness increases, the transparency becomes more opaque. Because the transparency of membranes tissue such as the cornea and dura mater are necessary, transparent membrane is required to replace these transparent membranes. In this study, we fabricated blending silk fibroin membranes that made by mixing the various inorganic salts or polymer in an aqueous solution of silk fibroin. The transparency of the membranes were analyzed. the transparency of these membranes is very different, depending on the mixed materials. Inorganic salts mixed silk membrane was more transparent than the polymer mixed one. Especially, the silk fibroin membrane with calcium chloride was very transparent. We showed the possibility of blending silk fibroin membrane, which can be used in perfect transparent membrane such as the cornea. In the future, we expect that the transparent blending silk fibroin membrane can be used in various medical applications.