Abstract: A damage control unit includes: a switching judgment unit to judge the CPU configuration which performs smoothing of the damage ratio, according to the damage ratio of the CPUs; and a switching unit to perform switching of I/O signals of all the CPUs. The switching judgment unit observes the damage ratio calculated from values such as the temperature, voltage, current consumption amount, operation ratio, the number of accesses to the resources in the CPU, at all times or at some extent of time intervals and notifies the switching unit of the CPU configuration to be changed by using the calculation method for smoothing the damage ratio of each CPU. The switching unit makes a connection to the I/O signals of all the CPUs and a system bus and switches the I/O signal of the CPU to be switched according to the notification from the switching judgment unit.