A plurality of fuel nozzles X1, and X2 in combustor X are supplied with fuel gas from a fuel gas system and fuel oil from a fuel oil system, respectively. The switching is based on a Musical Instrument Digital Interface view-switching track associated with a project file for the audio. A control unit performs the position control operation to monitor the measurement of a position detector such as a laser interferometer, stop driving the center table at a designated stop position, and separate the table and the X rod from each other using the gap. 01 to 10% by weight of one or more kinds of specific polysaccharides.