NOVELTY - A fuel cell (1A) comprises catalyst layers (3A,3B), gas diffusion layers (5A,5B) and collectors (6A,6B) laminated sequentially on either sides of an electrolyte membrane (2). Humidity control layers (9A,9B) are provided on the other side of collectors.    USE - Fuel cell such as bio-fuel cell, alkali electrolyte type fuel cell, phosphoric acid fuel cell, molten carbonate fuel cell, solid oxide fuel cell and direct methanol fuel cell, is used as power supply of small-sized electronic device (claimed).    ADVANTAGE - Since the humidity control layer is provided apart from the collector (electrode), sufficient amount of water can be supplied with respect to electric power generation portion by absorption and release effect of water in humidity control layer, without impairing the electrode structure. Therefore, reduction in mechanical strength of collector and increase in internal resistance of electrode are prevented. The drying of electrolyte membrane by heat emission produced by the generation of methanol crossover is suppressed. The fuel cell has reduced size, improved output characteristics and energy efficiency.    DETAILED DESCRIPTION - A fuel cell comprises catalyst layers, gas diffusion layers and collectors laminated sequentially on either sides of an electrolyte membrane. Humidity control layers are provided on the other side of collectors. The humidity control layer is formed using a water-absorptive material containing granules of water-absorbing resin, water absorptive inorganic substance or short fiber. Preferably, the water-absorptive material is a sheet-like moisture absorptive and releasing fiber. Water repellent layers (4A,4B) comprising conductive material is provided between catalyst layer and gas diffusion layer.    DESCRIPTION OF DRAWING(S) - The drawing shows the sectional view of fuel cell. (Drawing includes non-English language text)    Fuel cell (1A)    Polymer electrolyte membrane (2)    Catalyst layers (3A,3B)    Water repellent layers (4A,4B)    Gas diffusion layers (5A,5B)    Collectors (6A,6B)    Humidity control layers (9A,9B)