An electronic control device includes: a logic circuit for reconfiguring a plurality of arithmetic circuits including a first circuit and a second circuit; a reconfiguration controller that reconfigures the arithmetic circuits and checks the reconfigured arithmetic circuits based on reconfiguration commands; and a process controller that transmits the reconfiguration commands to the reconfiguration controller and instructs the arithmetic unit to execute operations, in which when a first reconfiguration command is received, the reconfiguration controller reconfigures and checks the first circuit, when the check of the first circuit by the reconfiguration controller is completed, the process controller instructs the first circuit to execute an operation, the process controller transmits a second reconfiguration command to the reconfiguration controller and instructs the reconfiguration controller to start to reconfigure the second circuit until the execution of a predetermined process of the first circuit is completed after completion of the reconfiguration of the first circuit.