PROBLEM TO BE SOLVED : To avoid leakage of personal information without having cumbersome operation performed.SOLUTION : A property information service system 1 makes a memory part 24 of an image formation device 3 store a box setting table 60 in which items of an encryption setting 62 and information addition setting 64 and the like are associated with each transaction status, and in a case the transaction status of the real estate property is updated by the operation of a client, the system is configured to perform the corresponding task automatically based on each setting Thereby, the property information service system 1 comes to encrypt/decrypt the information, or add/delete the private information, automatically upon client' s operation for updating the transaction status of a real estate property. Therefore, it allows the clients to access to the information necessary for proceeding their transactions while securely preventing the leakage of personal information.SELECTED DRAWING : Figure 14COPYRIGHT : (C)2018, JPO&INPIT