A cooling device for a fuel cell is provided which can maintain the electric conductivity of a liquid coolant within the predetermined range even if a load suddenly changes. In the cooling device for a fuel cell (10), the parameters (TH, TL) relating to the coolant temperature can be controlled so that the electric conductivity (S) at a target set temperature is maintained within a target electric conductivity range (Smax-Smin) based on the correlation between the parameters relating to the coolant temperature and the electric conductivity of the coolant. Because the electric conductivity is feed-forward controlled based on the correlation between the parameters relating to the coolant temperature and the electric conductivity of the coolant, the electric conductivity of the coolant can be reliably maintained within the target range even when electric conductivity with a comparatively poor responsiveness is controlled.