A management technique provides for management of power supply modules. In multiple computer equipment, in response to a load state, if an operation system issues a command that changes a processor state of a processor to a sleep state, a management module is notified through a management network MI that the processor state has changed. The management module holds a system information, and performs the steps of: updating system information because the processor state has changed; from this system information, calculating the power consumption required for the multiple computer equipment; determining the number of required AC-DC power supply modules to be operated; and changing the number of operating AC-DC power supply modules by use of a control interface PA.