Patent ID: 8278008

Claim:
A fuel cell separator, wherein: said fuel cell separator is formed in a plate shape and is provided on at least one main surface thereof with a reaction gas passage region through which a reaction gas flows, the reaction gas passage region being formed in a serpentine shape having a plurality of linear portions and one or more turn portions provided between the plurality of linear portions, said reaction gas passage region comprises: a plurality of flow splitting regions being formed so as to include at least said linear portions of said plurality of linear portions and said one or more turn portions, and having a passage groove group for splitting the reaction gas; and one or more flow merge regions formed in at least one of said one or more turn portions, said one or more flow merge regions having a recessed portion serving as a space in which the reaction gas is mixed and a plurality of protrusions that vertically extend from a bottom face of said recessed portion and are arranged in an island form, being disposed between the passage groove group of an adjacent upstream flow splitting region and the passage groove group of an adjacent downstream flow splitting region of said plurality of flow splitting regions, and being configured to allow the reaction gas flowing therein from said passage groove group of said upstream flow splitting region to merge in said recessed portion and to allow the reaction gas that has been merged to split again and flow into said downstream flow splitting region, in said upstream flow splitting region and said downstream flow splitting region that are connected to said recessed portion of said merge region, the number of grooves of said passage groove group of said upstream flow splitting region is greater than the number of grooves of said passage groove group of said downstream flow splitting region, said recessed portion of said flow merge region is, in said turn portion of said reaction gas passage region in which said recessed portion is formed, defined by an outer end of said turn portion and oblique boundaries between said recessed portion and a pair of said upstream passage groove group and said downstream passage groove group which are connected to said recessed portion, and said outer end curves in a position thereof to form an outer end protruding portion protruding toward said recessed portion.