Method of controlling sheet manufacturing apparatus

A method of controlling a sheet manufacturing apparatus that manufactures a sheet from a material containing fibers,

• the sheet manufacturing apparatus including
• a deposition portion that forms a web from the material by depositing the material,
• a transport portion that includes a transport belt which transports the web in a state that the web is supported,
• a humidifier that humidifies the web by discharging air mixed with water supplied from a tank which stores the water,
• a heating roller that is positioned downstream of the humidifier in a transport direction of the web and that heats the web to form the sheet from the web,
• a moisture meter that is positioned between the humidifier and the heating roller and that measures a moisture amount contained in the web,
• a thermometer that measures a temperature of the water stored in the tank, and
• a hygrometer that measures humidity outside the sheet manufacturing apparatus,
• the control method comprising:
• controlling, as a first mode, drive of the humidifier, based on at least one of a measurement result of the temperature of the water by the thermometer and a measurement result of the humidity by the hygrometer until when a leading end of the web reaches the moisture meter;
• and
• controlling, as a second mode, the drive of the humidifier, based on a measurement result of the moisture amount by the moisture meter after execution of the first mode.