An information processing device comprising: a plurality of processing units (3A∼3D) that each has a hardware resource including an arithmetic processing unit, a storage unit and a pair of memory areas (36A, 36B) arranged to store a firmware program controlling the hardware resource; and a system control unit (2A, 2B) that is arranged to control the plurality of processing units (3A∼3D), and to transmit an updated firmware program received from an external device to each of the processing units (3A∼3D), wherein each of the processing units (3A∼3D) is arranged to write the updated firmware program to one memory area in a state not used for the operation out of the pair of memory areas (36A,36B), characterized in that the system control unit (2A, 2B) is arranged to: detect a version of the firmware program used in operation in the pair of memory areas (36A, 36B) of each processing device (3A∼3D) and to judge whether or not the firmware program is compatible with the updated firmware program by comparing the detected version with a version of the updated firmware program, before writing the updated firmware program and during operation of each processing device (3A∼3D); instruct a stop and re-start to all the processing units (3A∼3D) after writing the updated firmware program when judging there is no-compatibility; and write the updated firmware program to the one memory area without stopping the processing units and switch the one memory area from the state not used in the operation to a state of use in each processing unit (3A∼3D) at a next start or re-start when judging there is compatibility, wherein each of the processing units is arranged to re-start and switch the one memory area from the state not used in the operation to the state of use in response to the re-start instruction. a plurality of processing units (3A∼3D) that each has a hardware resource including an arithmetic processing unit, a storage unit and a pair of memory areas (36A, 36B) arranged to store a firmware program controlling the hardware resource; and a system control unit (2A, 2B) that is arranged to control the plurality of processing units (3A∼3D), and to transmit an updated firmware program received from an external device to each of the processing units (3A∼3D), wherein each of the processing units (3A∼3D) is arranged to write the updated firmware program to one memory area in a state not used for the operation out of the pair of memory areas (36A,36B), characterized in that detect a version of the firmware program used in operation in the pair of memory areas (36A, 36B) of each processing device (3A∼3D) and to judge whether or not the firmware program is compatible with the updated firmware program by comparing the detected version with a version of the updated firmware program, before writing the updated firmware program and during operation of each processing device (3A∼3D); instruct a stop and re-start to all the processing units (3A∼3D) after writing the updated firmware program when judging there is no-compatibility; and write the updated firmware program to the one memory area without stopping the processing units and switch the one memory area from the state not used in the operation to a state of use in each processing unit (3A∼3D) at a next start or re-start when judging there is compatibility, wherein each of the processing units is arranged to re-start and switch the one memory area from the state not used in the operation to the state of use in response to the re-start instruction.