A cluster system coupled to a client computer via a network has plural nodes which provide services to the client computer. The base member contains an open-topped chamber and includes a vertical front wall the upper edge of which contains a vertical slot communicating with the chamber. The dust collection seat is divided by a partition to form a filter chamber and an airflow chamber that communicate with each other. The waveguide is formed on the substrate and includes an output section including an output end and at least two input branches branching off from an end of the output section opposite to the output end. The moving member can be moved through the window between a first position, where the tip is retracted and the second position, where the tip is exposed.