Method of producing fuel cell stack

A method of producing a fuel cell stack formed by stacking a plurality of power generation cells, the power generation cells each comprising:

• a first metal separator provided on one surface of a membrane electrode assembly, and a second metal separator provided on another surface of the membrane electrode assembly;
• a bead seal provided on a surface of each of the first metal separator and the second metal separator facing the membrane electrode assembly and protruding toward the membrane electrode assembly;
• and
• a seal member interposed between a top part of the bead seal and the membrane electrode assembly,
• the method comprising:
• a stacking step of stacking the plurality of power generation cells together to obtain the fuel cell stack;
• and
• a pressure medium supplying step of supplying pressure medium to a coolant flow field formed between the first metal separator and the second metal separator,
• wherein, in the pressure medium supplying step, the pressure medium is supplied at a supply pressure of not less than a supply pressure of a coolant supplied to the coolant flow field during normal operation of the fuel cell stack.