This invention relates to the presence of slightly or non-porous zones in the electrode layer around gas inlets, in order to improve the leak tightness between the different individual cells making up a fuel cell with a plane geometry. The fuel cell comprises a first electrode layer having a non-porous zone forming a passage therethrough for gas flow and an electrolyte layer having a protuberance which extends into the first electrode layer for forming the non-porous zone with the non-porous zone representing a gas tight passage. Nested contact between the bipolar plate and the ceramic triple layer making up the basic cell is also described and is another possible means of avoiding mixes of gasses.