An electronic control unit for a moving body, the electronic control unit comprising: a first CPU (Central Processing Unit: 11); and a second CPU, wherein each of the first and second CPUs is configured to monitor an operation of the other one of the first and second CPUs, and wherein each of the first CPU and the second CPU is provided with: a test value acquiring unit (31, 41) configured to acquire a test value; a test computing unit (32, 42) configured to perform a computing process by using the test value and a common value to calculate a computation value; and a comparing unit (33, 43) configured to perform an inverse computation of the computation value calculated by the other one of the first and second CPUs by using the common value, and to compare a result of the inverse computation with the test value of the one of the first and second CPUs to determine an operation of the other one of the first and second CPUs, wherein the test value acquiring unit of the first CPU is configured to acquire a code indicating a result of a self-diagnosis on a core of the first CPU as the test value, and the test value acquiring unit of the second CPU is configured to acquire a code indicating a result of a self-diagnosis on a core of the second CPU as the test value, and the test computing units (32, 42) of the first CPU and second CPU are configured to calculate the computation value while changing the computing process in a sequential manner every predetermined times. a first CPU (Central Processing Unit: 11); and a second CPU, wherein each of the first and second CPUs is configured to monitor an operation of the other one of the first and second CPUs, and wherein each of the first CPU and the second CPU is provided with: a test value acquiring unit (31, 41) configured to acquire a test value; a test computing unit (32, 42) configured to perform a computing process by using the test value and a common value to calculate a computation value; and a comparing unit (33, 43) configured to perform an inverse computation of the computation value calculated by the other one of the first and second CPUs by using the common value, and to compare a result of the inverse computation with the test value of the one of the first and second CPUs to determine an operation of the other one of the first and second CPUs, wherein a test value acquiring unit (31, 41) configured to acquire a test value; a test computing unit (32, 42) configured to perform a computing process by using the test value and a common value to calculate a computation value; and a comparing unit (33, 43) configured to perform an inverse computation of the computation value calculated by the other one of the first and second CPUs by using the common value, and to compare a result of the inverse computation with the test value of the one of the first and second CPUs to determine an operation of the other one of the first and second CPUs, wherein the test value acquiring unit of the first CPU is configured to acquire a code indicating a result of a self-diagnosis on a core of the first CPU as the test value, and the test value acquiring unit of the second CPU is configured to acquire a code indicating a result of a self-diagnosis on a core of the second CPU as the test value, and the test computing units (32, 42) of the first CPU and second CPU are configured to calculate the computation value while changing the computing process in a sequential manner every predetermined times.