A fuel cell stack includes a plurality of power generation cells stacked and connected in series and coolant passages configured to circulate coolant. The power generation cells each include a membrane electrode assembly and two separators sandwiching the membrane electrode assembly. The separators are each formed by a metal plate. The coolant passages include through-holes extending through the separators and aligned in a stacking direction of the power generation cells. A method for manufacturing a fuel cell stack includes forming a coating of electrodeposition paint on surfaces of ones of the separators having a high electric potential in the fuel cell stack by operating the fuel cell stack and using the coolant that contains electrodeposition paint particles.