Fuel cell

A fuel cell formed by stacking an electrolyte electrode assembly and a separator in a stacking direction, the electrolyte electrode assembly including electrodes and an electrolyte interposed between the electrodes, a reactant gas supply passage and a reactant gas discharge passage extending through the fuel cell for allowing a reactant gas to flow in the stacking direction, a reactant gas flow field being formed between the electrolyte electrode assembly and the separator for allowing the reactant gas to flow along an electrode surface, the separator including an inlet connection channel portion connecting the reactant gas supply passage and the reactant gas flow field and an outlet connection channel portion connecting the reactant gas flow field and the reactant gas discharge passage,

• the reactant gas flow field including:
• an inlet channel having a plurality of continuous and uninterrupted flow grooves coupled to the reactant gas supply passage;
• an outlet channel having a plurality of continuous and uninterrupted flow grooves coupled to the reactant gas discharge passage;
• and
• an intermediate channel having a plurality of continuous and uninterrupted flow grooves with both ends connected to the inlet channel and the outlet channel respectively,
• wherein the flow grooves of the outlet channel are longer than the flow grooves of the inlet channel.