NOVELTY - The method comprises feeding a polymer electrolyte membrane and sub-gaskets (16) into an alignment device, feeding the aligned polymer electrolyte membrane and sub-gaskets into an ultrasonic vibration applying device (30), bonding the sub-gaskets to edges of both sides of the polymer electrolyte membrane by ultrasonic vibration, spray coating an electrode slurry on both sides of the polymer electrolyte membrane, and drying the coated electrode slurry. After bonding the sub-gaskets, the edges of both sides of the polymer electrolyte membrane are fixed by the sub-gaskets.    USE - The method is useful for manufacturing a fuel cell membrane-electrode assembly by ultrasonic vibration bonding.    ADVANTAGE - The method prevents damage to the membrane-electrode assembly by an ultrasonic vibration horn, and improves physical durability and power output of the membrane-electrode assembly.    DETAILED DESCRIPTION - The method comprises feeding a polymer electrolyte membrane and sub-gaskets (16) into an alignment device, feeding the aligned polymer electrolyte membrane and sub-gaskets into an ultrasonic vibration applying device (30), bonding the sub-gaskets to edges of both sides of the polymer electrolyte membrane by ultrasonic vibration, spray coating an electrode slurry on both sides of the polymer electrolyte membrane, and drying the coated electrode slurry. After bonding the sub-gaskets, the edges of both sides of the polymer electrolyte membrane are fixed by the sub-gaskets, and the electrode slurry is directly coated on both sides of the polymer electrolyte membrane. The step of feeding the polymer electrolyte membrane and sub-gaskets into the ultrasonic vibration applying device comprises feeding a stacked layer comprising the polymer electrolyte membrane with the sub-gaskets stacked on both sides of the polymer electrolyte membrane. Each sub-gasket has an opening in a central portion exposing the polymer electrolyte membrane, and the step of coating the electrode slurry on both sides of the polymer electrolyte membrane comprises coating the exposed polymer electrolyte membrane on both sides.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a method for manufacturing a fuel cell membrane-electrode assembly.    Sub-gasket (16)    Sub-gasket supply roll (22)    Alignment device (24)    Support roll (26)    Ultrasonic vibration applying device. (30)