Patent ID: 8354200

Claim:
A membrane which adjusts a fuel distribution, the membrane being provided in a fuel supply side of a membrane electrode assembly of a fuel cell, the membrane electrode assembly including an anode electrode, a cathode electrode, and an electrolyte membrane provided between the anode electrode and the cathode electrode, the membrane having a plurality of through-holes through which fuel passes, a major surface of the membrane having a central region including a central portion of the membrane, an intermediate region surrounding the central region, and a peripheral region surrounding the intermediate region, the central region having through-holes, the intermediate region having through-holes and the peripheral region having through-holes, an array of the through-holes in the intermediate region surrounding an array of the through-holes of the central region, and an array of the through-holes of the peripheral region surrounding the array of the through-holes of the intermediate region, the central region, the intermediate region and the peripheral region are concentric, the through-holes in the central region having an opening rate lower than an opening rate of the through-holes in the intermediate region, the opening rate of the through-holes in the intermediate region being lower than and opening rate of the through-holes in the peripheral region, and the opening rates of the through-holes of the central region, the intermediate region and the peripheral region changing concentrically.