An electronic control device includes a processing control unit and an information acquisition unit. The information acquisition unit collects and transfers external environment information to the processing control unit, the processing control unit includes a first processor, a second processor, and a storage unit, the processing control unit executes arithmetic processing by a non-redundant and redundant processing configuration that executes non-redundant and redundant processing using the first processor and the second processor, respectfully, and the processing control unit stores a result of arithmetic processing by the non-redundant processing configuration in the storage unit, individually performs arithmetic processing using the stored result in both the first processor and the second processor by arithmetic processing by the redundant processing configuration, and performs determination for an arithmetic processing result by the non-redundant processing configuration based on an arithmetic result by the first processor and an arithmetic result by the second processor.