1. A policy management apparatus comprising: a role information storing unit that stores role information including information indicative of subject sets to which policies are to be applied, and information capable of specifying inclusion relationships between subject sets contained in said role information; a policy description storing unit that stores policy descriptions including information indicative of policies and information for identifying subject sets to which said policies are to be applied; a policy stratifying unit that, for two or more policies stored in said policy description storing unit, generates a policy hierarchy map in which each of two or more policies are stratified within said policy hierarchy map based on inclusion relationships between subject sets to which each of said two or more policies are applied by assuming that each policy is a node; and a policy ordering unit that orders policy sets made of said two or more policies in a row by arranging said two or more policies in an order of deep layer to shallow layer or order of shallow layer to deep layer based on said policy hierarchy map generated by said policy stratifying unit.