Input-output devices are prevented from conducting false output due to faulty operation by providing an input-output control apparatus configured to store input-output values to be used by a processor to conduct arithmetic operation in a mode having a relatively high safety requirement, in a first storage area, store input-output values to be used by the processor to conduct arithmetic operation in a mode having a relatively low safety requirement, in a second storage area, and restrict copying to the first storage area, copying from the first storage area, copying to the second storage area, or copying from the second storage area according to the mode concerning the safety requirement.