Patent ID: 7264233

Claim:
A humidifier which is used for a fuel cell that generates electricity by means of a chemical reaction of anode gas supplied to the anode and cathode gas supplied to the cathode, and exhausts anode off-gas from the anode and cathode off-gas from the cathode, comparing: a housing having a first area for passing a first gas and a second area for passing a second gas having higher water content than that of the first gas, the first gas being either the anode gas or the cathode gas, and the second gas being at least either the anode off-gas or the cathode off-gas; a moisture permeable means for transferring moisture from the second gas to the first gas to humidify the first gas; a liquid pool portion for pooling condensed water formed in the first area; and a communicating path formed on the housing through which the first area and the second area communicate with each other, with one end of the communicating path being positioned at the liquid pool portion, to transfer condensed water formed in the first area to the second area.