Disclosed is a fuel cell system. The fuel cell system according to an embodiment of the present invention comprises: a fuel cell stack; a heat exchanger for recovering and storing thermal energy generated in the fuel cell stack; a heat storage part for storing warm water heated while circulating through the heat exchanger; a temperature sensor for detecting the temperature of the warm water stored in the heat storage part; and a control part for controlling the operation of the fuel cell system according to the temperature detected by the temperature sensor and target power generation for each configured time interval.
