PURPOSE: To make it possible to take out a plurality of keys simultaneously.

CONSTITUTION: In a key box 1A in which a security level is installed so as to discriminates IDs so that it may be possible to open at least two housing units in the key box 1A on a specified card. More specifically, in the key box 1A, which allows each room key to be housed in each electromagnetically locked housing unit 13 and the electromagnetic lock to be selectively released by a card reader which reads an ID card, a single predetermined housing unit under one's own control or more than two housing units 13 are simultaneously unlocked, responding to the security level of the card reader.