To uniformly maintain a wet state of a reaction layer in a fuel cell all the time.

The reaction layer is interposed between a solid electrolyte film and a diffusion layer in a fuel cell. The reaction layer includes: a first layer which comes into contact with the solid electrolyte film; a second layer which comes into contact with the diffusion layer; and an intermediate layer which is interposed between the first layer and the second layer. The first layer is moister than the second layer, and no catalyst is present in the intermediate layer.

COPYRIGHT: (C)2011,JPO&INPIT