PURPOSE: To manage automatically a rental box in common use for a post-office box by depressing a new contract button, paying a charge with a prescribed procedure to allow the box to issue an ID card and opening/closing a door of the box with the ID card.

CONSTITUTION: When a new contract push button is depressed to operate a pushbutton switch 31, an operation procedure is displayed on a display device 48. Then a ten-key and a KANA (Japanse syllabary) entry key board are operated to operate a KANA letter entry key board switch 33 to enter data such as address, name, age, and telephone number. The data are entered correctly to deposit a prescribed charge and an ID card purchase confirmation button is depressed, then an ID card issue control section 41 controls a card writer 42 and then an ID card is issued. When an issued ID card is inserted to an Id card purchase port, an ID card reader 34 reads contents of the ID card and when normal, a door switching control section 43 conducts door lock unlock control. Then a thing in a box is extracted and the door is closed by a hook and the door closing button is depressed to lock the door.