An evaporative humidifier for a polymer electrolyte membrane fuel cell system including a fuel cell stack, comprising: a condensation channel to which exhaust gas from the fuel cell stack is introduced; an evaporation channel to which supply gas for the fuel cell stack is introduced; a partition wall for separating the condensation channel and the evaporation channel from each other; and a water distribution unit for supplying water into the evaporation channel, wherein the water is condensed in the condensation channel by heat exchange between the exhaust gas and the supply gas.