Condensation suppressing method and processing apparatus

A condensation suppressing method in a processing apparatus configured to process a processing target object,

• wherein the processing apparatus comprises:
• a first temperature measuring unit configured to measure a surface temperature of a first member exposed in a first closed space provided in the processing apparatus;
• a supply line through which a low-dew point gas having a dew point temperature lower than that of air outside the processing apparatus is supplied into the first closed space;
• and
• a control unit configured to control a flow rate of the low-dew point gas supplied into the first closed space, and
• wherein the control unit performs:
• a first process of specifying an absolute humidity of a gas within the first closed space at a position of a surface of the first member for the flow rate of the low-dew point gas;
• a second process of specifying a saturated absolute humidity at the surface temperature of the first member measured by the first temperature measuring unit;
• and
• a third process of controlling the flow rate of the low-dew point gas based on the absolute humidity of the gas within the first closed space at the position of the surface of the first member and the saturated absolute humidity at the surface temperature of the first member.