An apparatus for storing a medium includes a safe having an entrance for replenishment and recovery to which a transit cassette is selectively connected, a reception unit configured to deposit and withdraw a medium by a customer, an identification unit serving to identify whether the medium is a normal banknote or a rejection banknote, a deposit cassette configured to store the medium deposited through the reception unit, a recycle cassette configured to store the medium recognized as the normal banknote, a conveyance path configured to convey the medium, and a control unit configured to control the conveyance path.