In an information security management system (ISMS), based on Recommendation ITU-T X.1051 and ISO/IEC Standards 27001 and 27002, physical security is a key issue. When security is managed taking the above references into consideration, we should evaluate the threats and mitigate their impact against equipment or sites. Threats are related to confidentiality in ISMS. This recommendation describes threats from information leakage due to unintentional electromagnetic emanations, and the two approaches of mitigation i.e reduction of emission from equipment and the level of site shielding are described. Information leakage test methods for conducted and radiated emission are presented.