Power savings for a storage apparatus while preventing a drop in response performance is achieved. When the storage area supplied by the memory apparatus groups is not accessed by the host apparatus for a predetermined period, stop operation is performed for each of the memory apparatuses configuring the memory apparatus groups. The management apparatus groups, among the resources, resources with overlapping time zones for which the number of accesses by the application is zero, in the same group, and maps each of the groups to the memory apparatus groups respectively. At this time, if the number of accesses in each of the time zones of the groups of resources mapped to the memory apparatus groups exceeds the reference value of the memory apparatus groups, the group is divided into a plurality of groups and each of the plurality of groups is mapped to the memory apparatus groups.