Abstract: The present invention relates to a thermal management system and a thermal management method for cooling a heat-generating electronic device such as a battery and for extinguishing a fire occurring in the heat-generating electronic device. More particularly, the present invention relates to a thermal management system and a thermal management method that are capable of cooling a heat-generating electronic device such as a battery of an energy storage system (ESS) in various ways at multiple stages and of extinguishing a fire in the heat-generating electronic device. The present invention has an effect of preventing fire by cooling a heating-generating element such as a battery of an energy storage device. In addition, the present invention has an effect of stopping a cooling operation and starting a fire extinguishing operation when a fire occurs during the cooling operation.