Based on the security policy set in the original document and the security policy supported by the format of conversion destination, it is judged whether or not the security policy set in the original document is inheritable to the electronic document after format conversion. If it is judged that the security policy is inheritable, the security policy set in the original document is inherited to the electronic document after format conversion. If it is judged that the security policy is not inheritable, a process for inheriting the security policy set in the original document to the electronic document after format conversion is not performed.