Abstract: A device for regulating temperature and humidity of a reaction gas to be supplied to a fuel cell stack includes a temperature regulation section provided with a first gas guide board through which the reaction gas flows, a coolant guide board through which a coolant from the fuel cell stack flows and a first partition interposed between the first gas guide board and the coolant guide board for exchange of heat between the reaction gas and the coolant and a humidity regulation section coupled to the temperature regulation section with a second partition therebetween and comprised of a second gas guide board through which the temperature-regulated gas flows and a fluid guide board through which a fluid from the fuel cell stack and rich of water contents flows and a humidity exchange film interposed between the second gas guide board and fluid guide board to allow for exchange of water contents between the temperature-regulated gas and the fluid.