A processor includes a plurality of processing sections, each of which executes a predetermined process. A plurality of fault detecting circuits are respectively provided for the plurality of processing sections, to detect a fault in one of the plurality of processing sections as a fault processing section to generate a fault detection signal. A fault monitoring and control section controls a normal processing section as at least one of the plurality of processing sections other than the fault processing section to execute a relieving process in response to the fault detection signal. The relieving process is determined based on a process load of the fault processing section, a process load of the normal processing section, and priority levels of processes to be executed by the fault processing section and the normal processing section.