1. An access management apparatus which regulates access to each of a plurality of nodes stored hierarchically, the access management apparatus comprising: a function storage for storing a plurality of rule functions in association with a plurality of requesters, each of the rule functions determining whether access to a node should be permitted or rejected for a requester depending on the position of the node in the hierarchical structure; a receiver for receiving an access request from a requester for access to a requested node; a selector for selecting the rule function associated with the requester of the access request; an executor for receiving the position of the requested node as an input and for executing the rule function which has been selected by the selector to determine whether access to the requested node should be permitted or rejected; and a controller for controlling permission or prohibition of the access request based on the executing of the rule function.