NOVELTY - The fuel cell system has fuel cell (11) which produces electric power using fuel gas and oxidizing gas, fuel gas humidifier (20) which humidifies fuel gas supplied to the fuel cell, and oxidizing gas humidifier which humidifies oxidizing gas supplied to the fuel cell. Humidifier (20) humidifies by heating the moisture content in the fuel gas emitted from the fuel cell by cooling water after cooling of heat during electric power generation of fuel cell. The oxidizing gas humidifier is equipped with oxidizing gas humidifier (22) and oxidizing gas humidifier (21).    USE - Fuel cell system is used for electric power generation for electric vehicle.    ADVANTAGE - The fuel cell system is compact and inexpensive and has improved energy efficiency and excellent durability.    DETAILED DESCRIPTION - The fuel cell system has fuel cell (11) which produces electric power using fuel gas and oxidizing gas, fuel gas humidifier (20) which humidifies the fuel gas supplied to the fuel cell and oxidizing gas humidifier which humidifies the oxidizing gas supplied to the fuel cell. The fuel gas humidifier humidifies by heating the moisture content contained in the fuel gas emitted from the fuel cell by cooling water after cooling of heat during electric power generation of fuel cell. The oxidizing gas humidifier is equipped with oxidizing gas humidifier (22) and oxidizing gas humidifier (21). Humidifier (22) humidifies using the moisture content contained in the oxidizing gas emitted from the fuel cell. Humidifier (21) humidifies using the warm water of cooling water which cools the heat of fuel cell. The fuel gas humidifier, humidifier (22) and humidifier (21) are integrally formed by positional relation such that heat transfer is possible from each outer surface.    DESCRIPTION OF DRAWING(S) - The drawing shows the structure of the fuel cell system. (Drawing includes non-English language text)    Air paths (1-3)    Discharge air path (4)    Cooling water flow path (7)    Fuel cell (11)    Fuel gas humidifier (20)    Oxidizing gas humidifiers (21,22)