A fuel cell system for supplying anode gas and cathode gas to a fuel cell and causing the fuel cell to generate power according to a load, comprising: a component configured to circulate, through the fuel cell, discharged gas of either the anode gas or the cathode gas discharged from the fuel cell to the fuel cell; a power generation control unit configured to control a power generation state of the fuel cell on the basis of the load; a freezing prediction unit configured to predict the freezing of the component by a detection unit (41, 44, 43, 101) configured to detect a temperature of the fuel cell system; an operation execution unit configured to execute, in case of receiving a stop command of the fuel cell system when the freezing of the component is predicted a warm-up operation after the stop of the fuel cell system, wherein, in the warm-up operation, power is supplied from the fuel cell to auxiliary machines, and a dry operation unit configured to control the fuel cell to a predetermined dry state when a temperature of the fuel cell decreases to a predetermined freezing prevention threshold value Th_s after the fuel cell system is stopped, and wherein the operation execution unit is configured to execute the warm-up operation on the basis of the temperature of the fuel cell system when the dry operation unit controls the fuel cell to the dry state, and the freezing prediction unit is configured to set the freezing prevention threshold value Th_s higher as a difference between the amount of ice and a predetermined freezing prevention threshold value ThJ decreases if the amount of ice generated in the component is smaller than the predetermined freezing prevention threshold value Th_j, the freezing prevention threshold value Th_j being a threshold value for predicting the freezing of the component. a component configured to circulate, through the fuel cell, discharged gas of either the anode gas or the cathode gas discharged from the fuel cell to the fuel cell; a power generation control unit configured to control a power generation state of the fuel cell on the basis of the load; a freezing prediction unit configured to predict the freezing of the component by a detection unit (41, 44, 43, 101) configured to detect a temperature of the fuel cell system; an operation execution unit configured to execute, in case of receiving a stop command of the fuel cell system when the freezing of the component is predicted a warm-up operation after the stop of the fuel cell system, wherein, in the warm-up operation, power is supplied from the fuel cell to auxiliary machines, and a dry operation unit configured to control the fuel cell to a predetermined dry state when a temperature of the fuel cell decreases to a predetermined freezing prevention threshold value Th_s after the fuel cell system is stopped, and wherein the operation execution unit is configured to execute the warm-up operation on the basis of the temperature of the fuel cell system when the dry operation unit controls the fuel cell to the dry state, and the freezing prediction unit is configured to set the freezing prevention threshold value Th_s higher as a difference between the amount of ice and a predetermined freezing prevention threshold value ThJ decreases if the amount of ice generated in the component is smaller than the predetermined freezing prevention threshold value Th_j, the freezing prevention threshold value Th_j being a threshold value for predicting the freezing of the component.