In a fuel cell assembly with at least one cell including an electrolyte
layer, a pair of gas diffusion electrode layers interposing said
electrolyte layer between them, and a pair of flow distribution plates
(5) for defining passages (10, 11) for fuel and oxidizer gases that
contact said gas diffusion electrode layers, a heater 62 and various
sensors (61a, 61b and 61c) are formed on at least one of the flow
distribution plates so that the work needed for installing the heater and
sensors is simplified. By embedding them in a substrate, the need for a
complex sealing arrangement can be eliminated. In particular, if each
flow distribution plate is formed by performing an etching process on a
substrate, and forming the heater and sensors in succession to the step
of forming each flow distribution plate, the installation of sensors and
fabrication of the fuel call are simplified.