PURPOSE: To deliver freight even at the time of the absence of a recipient while ensuring delivery and receipt by depressing and locking a master key installed to an operating section and issueing a key having a random code for release.

CONSTITUTION: When a recipient is absent on delivery, a card-shaped key is discharged from a key doorway 5 while a buzzer 6 is rung when the master key 7 of its own company is set, the door 1 of a housing section not used is opened and an article to be delivered is housed and a locking button 3 is depressed. The key is extracted, the buzzer 6 is rung off and the key is put into an envelope, and the envelope is charged into a mailbox. The recipient receiving the key signs or seals the key and inserts the key into the key doorway 5, a lock is released when the key coincides with the lock, and the door 1 is opened and the article to be delivered is received. The signed (sealed) key is recovered, thus acquiring a receipt.