HUMIDIFIER FOR FUEL CELL

The present invention relates to a humidifier for a fuel cell, the humidifier comprising: a humidification module for humidifying dry gas supplied from the outside by using wet gas discharged from a fuel cell stack; a mid-case including a first cap coupled to one end of the humidification module and a second cap coupled to the other end of the humidification module, both ends of the humidification module being open; a first gas inlet and a first gas outlet formed on one side of the mid-case; and a hollow fiber membrane bundle accommodated inside the mid-case along the lengthwise direction, wherein the hollow fiber membrane bundle includes a plurality of first hollow fiber membranes, the first hollow fiber membranes each independently include a first hollow, and the center of each of the first hollows is offset toward the other side of the mid-case with respect to the center of each of the first hollow fiber membranes.