A cleaning control method accurately detects the nozzle recovery condition after cleaning and efficiently eliminates ejection problems. Each production chamber has opposed ends with through openings and is connectable to a vacuum source. The second host may be adapted to perform the act of communicating without use of an intermediate server. The via is provided in a via hole extending from the first major surface side to the second major surface side of the semiconductor substrate. A timing device deactivates said warning light after a preset time interval or the device is deactivated when the stimulus for the activation means exits the area.