FUEL CELL HUMIDIFIER OF WHICH HOLLOW FIBER MEMBRANES CAN BE LENGTH-ADJUSTED, AND FUEL CELL HUMIDIFIER OF WHICH GAPS BETWEEN HOLLOW FIBER MEMBRANES CAN ADJUSTED

A humidifier for a fuel cell with a length of a hollow fiber membrane or a gap between hollow fiber membranes, which is adjusted in response to an internal temperature of the humidifier changing with an output condition of the fuel cell, includes a housing, the hollow fiber membrane located inside the housing and inside of which dry air flows and outside of which moist air flows, and a potting material located at opposite ends of the hollow fiber membrane and fixing a terminal end of the hollow fiber membrane, in which a first temperature-sensitive volume-changing member that expands and contracts according to temperature is inserted into the potting material such that, with respect to the first temperature-sensitive volume-changing member, the potting material is divided into an inner potting material located on an inner side of the housing and an outer potting material located on an outer side of the housing and spaced apart from the inner potting material.