Fuel cell stack

A fuel cell stack in which cooling water flows to a space defined by an anode separator and a cathode separator facing each other in adjacent cells, comprising:

• a cooling water diffusion portion provided on each of the anode separator and the cathode separator to introduce the cooling water from a cooling water manifold by distributing the cooling water on a reaction surface of the separators;
• a first cooling water flow path area disposed between a land formed on the cooling water diffusion portion of the anode separator and a channel formed on the cooling water diffusion portion of the cathode separator;
• and
• a second cooling water flow path area disposed between a channel formed on the cooling water diffusion portion of the anode separator and a land formed on the cooling water diffusion portion of the cathode separator,
• wherein the first cooling water flow path area and the second cooling water flow path area are parallel with each other within at least a part of the cooling water diffusion portion.