To provide a file cover for preventing the buckling of a file cover or the misalignment in which a file tends to be arched due to difference in thickness of file in the back and forth direction when binding documents to store, as files, the files to be bound with covers, stood vertically, and placed side by side on a bookshelf or the like.

When storing files to be stood vertically and placed side by side on the bookshelf or the like, the back spine cover 1 is attached in order to prevent the occurrence of the buckling and misalignment.