To provide a file structured so as to make it difficult to remove papers by a reader.

The file F comprises: a file main body 1; a binder 2 attached to the file main body 1; a permission element receiving part 7 which receives a card key 6 as a release operation permitting element used for controlling a state of the binder 2 as it is bound and a state of papers as they can be inserted/removed; and an operation restricting mechanism 8 which restricts the release operation as an operation during changing the binder 2 from the binding state to the release state, when the permission element receiving part 7 is not in the card key 6 receiving mode.