PROBLEM TO BE SOLVED : To provide a key system for a rental house, which provides a tenant with high security, almost completely eliminates the burden of a key management job on a real estate agent, makes it unnecessary to make a member of the real estate agent accompany a customer in a preview, and easily and surely brings about a lockout state, in a rental apartment building. SOLUTION : This rental house management system comprises an indoor terminal 10 which is arranged in each room of the rental house so as to control a lock provided in an entrance door, and a rental house management device which is connected to the indoor terminal 10. The indoor terminal 10 stores a transmitted unlocking personal identification code, dedicated to the preview, in an unlocking personal identification code storage portion 11a when the unlocking personal identification code is transmitted from the management device, and inhibits the reception of all the unlocking personal identification codes which are transmitted from the management device, when the unlocking personal identification code input from a terminal body' s numeric keypad/setting button 7a as a personal identification code input portion has already been stored in the storage portion 11a. COPYRIGHT : (C)2008, JPO&INPIT