NOVELTY - The polymer electrolyte fuel cell (150) has membrane electrode assembly (100) comprising catalyst layer (120a,120c) and polymer electrolyte film (110), and separator (140a,140c) having gas passageway (141). The catalyst layer contains electrode catalyst consisting of catalyst particles supported by carbon support. The catalyst layer has catalyst layer (122a,122c) contacting electrolyte film (110), and catalyst layer (121a,121c) contacting assembly (100). The support in layer (120a) has high crystallinity towards entrance side of gas passageway in separator.    USE - As power supply for motor vehicle (claimed).    ADVANTAGE - The polymer electrolyte fuel cell has high electric power generation capability over long period, improved electron transfer resistance of catalyst layer and suppresses corrosion of carbon support in catalyst layer efficiently.    DETAILED DESCRIPTION - The polymer electrolyte fuel cell (150) has a membrane electrode assembly (100) comprising a pair of catalyst layer (120a,120c) arranged on both sides of a solid polymer electrolyte film (110) clamped between a separator (140a,140c) having a gas passageway (141). The catalyst layer contains at least an electrode catalyst consisting of catalyst particles supported by a carbon support, and a solid polymer electrolyte. The catalyst layer is a laminate comprising catalyst layer (120a,120c) and another catalyst layer (121a,121c). The catalyst layer (120a) which does not have a crack (123a), contacts the polymer electrolyte film (110). The catalyst layer (121a) having a crack contacts the membrane electrode assembly (100) on the thickness direction. The carbon support contained in catalyst layer (120a) has high crystallinity towards the entrance side of gas passageway in separator to the exit side.    An INDEPENDENT CLAIM is included for motor vehicle.    DESCRIPTION OF DRAWING(S) - The figure shows the cross-section of the polymer electrolyte fuel cell.    Membrane electrode assembly (100)    Polymer electrolyte film (110)    Catalyst layers (120a,120c,121a,121c,122a,122c)    Crack (123a,123c)    Separator (140a,140c)    Gas passageway (141)    Polymer electrolyte fuel cell (150)