When copying data, it is desired to securely execute data management by preventing violation of rules or leaking out of secret information by administrative error. For this purpose, in a data processing method, for each storage area such as a volume in a storage device or a logical volume, a possible data arrangement range of data included in the storage area is stored. In addition, range information is defined for a copy-destination storage area. Then, when copying data in a storage area, a judgment is made as to whether or not the range information of the copy-destination storage area is within the possible data arrangement area of the data. If the range information is within the possible data arrangement area, copying will be executed. If the range information is not within the possible arrangement area, the copy processing will not be initiated.