An access management apparatus receives a command message having setting and changing functions, performs corresponding processing, and transmits results. A checking unit checks the presence/absence of a data element to be accessed. Access is permitted based on looking up a setting access condition if the data element is not set and looking up a changing access condition if the data element is set. A control table contains identification information, location information, a data setting access condition, and a data changing access condition of each of a plurality of data elements. When receiving a command, a determining unit determines whether the designated data element is already set by looking up location information of the data element in the control table. A data setting/changing unit sets or changes data in accordance with the access condition looked up.