MEMBRANE HUMIDIFIER FOR FUEL CELL, COMPRISING MULTI-CHANNEL HOLLOW FIBER MEMBRANES

Disclosed is a membrane humidifier for a fuel cell, comprising multi-channel hollow fiber membranes having a plurality of channels in various sizes, thus allowing humidifying performance to be maintained in the case of a high rate of flow and to be decreased in the case of a low rate of flow, and thereby preventing flooding. The membrane humidifier for a fuel cell, according to the present invention, comprises: a middle case in which a plurality of hollow fiber membranes are accommodated; a cap case coupled to the middle case; and a fixing unit in which ends of the plurality of hollow fiber membranes are potted, wherein a plurality of channels are formed in each of the hollow fiber membranes, and the difference between the biggest and smallest inner diameters among the inner diameters of the plurality of channels is 30-600 µm.