Lupin calls the Mint the Ministry of Economy Printing Bureau, Daito (or Big Eastern) Factory. This factory itself doesn't exist in real life. Back in the 1970s, actual bank bills were printed by the Ministry of Finance's Minting Bureau at an unspecified factory to avoid being a target for criminals. The Ministries were probably renamed for this episode just to make it sound legitimate. Nowadays, bank bills are issued by the Incorporated Administrative Agency, Japan Mint.