A method and device for managing a task upraised according to receiving a processing request of services in in-vehicle electronic control units are provided. The method and device include the steps of: allocating a plurality of services to one task and determining whether or not the task assigned with the service is in process of execution in receiving the processing request of the service; and upraising the task to process the service of the received processing request when determination is made that the task is not in process of execution in the determining step, and making the task in process of execution continuously process the service of the received processing request without newly upraising the task when determination is made that the task is in process of execution in the determining step.