NOVELTY - Fuel cell system has liquid storage portion (10), reaction portion (13), supply path (11), fuel cell (15), hydrogen circulation path (14), condenser (20), connection path (25) and driving channel (30). Fuel cell has cathode chamber (16) for storing hydrogen, and generates electric power by electrochemical reaction of hydrogen. Channel (30) has non-return valve (31), which prevents back flow of generated water.    USE - As fuel cell system.    ADVANTAGE - The fuel cell system has improved energy density and output characteristics. The required amount of electric power is reduced. The generated water is recovered, mixed with a fuel and used as fuel source.    DETAILED DESCRIPTION - Fuel cell system has a liquid storage portion (10), a reaction portion (13), a supply path (11), a fuel cell (15), a hydrogen circulation path (14), a condenser (20), a connection path (25) and a driving channel (30). The portion (10) stores primary quality of hydrogen generating material (A) and secondary quality of hydrogen generating material (B). The reaction portion reacts materials (A,B) and generates hydrogen. The supply path supplies material (A) to reaction portion from the liquid storage portion, and has non-return valve (12), which prevents back flow of the material (A) from reaction portion to liquid storage portion. The fuel cell has a cathode chamber for storing hydrogen, and generates electric power by carrying out electrochemical reaction of hydrogen. The path (14) supplies hydrogen to cathode chamber from reaction portion. The condenser stores generates water produced from cathode chamber interior. The connection path has non-return valve (26), which prevents back flow of generated water from condenser to cathode chamber. The driving channel has a non-return valve (31), which prevents back flow of generated water from reaction portion to the condenser.    DESCRIPTION OF DRAWING(S) - The figure shows the block diagram of the fuel cell system. (Drawing includes non-English language text).    liquid storage portion (10)    supply path (11)    non-return valves (12,26,31)    reaction portion (13)    hydrogen circulation path (14)    fuel cell (15)    cathode chamber (16)    condenser (20)    connection path (25)    driving channel (30)