In this research, we aim at to develop design environment which allow changing a robot's internal composition flexibly and easily by applying the RT-Middleware. To achieve this, we propose to introduce the manager, named RTM-PnP manager, which supports Plug and Play for RT-Component. This RTM-PnP manager that automatically negotiates and sets RT-Middleware is investigated to reduce complex sets up procedure to use OpenRTM-aist-0.4.x. For instance, in the start-up process, the robot cannot execute the requested service if the application program failed to manage RT-Component appropriately. By introducing PnP service, it becomes possible to change composition of the robot easily according to a user's environment or a request. Thereby development efficiency of the robot would be improved.