NOVELTY - Device for manufacturing platinum-silver alloy catalyst, comprises a container (10) for accommodating a fluid (11); a platinum electrode (21) mounted on one side of the container; a silver electrode (22) mounted on opposite side of the platinum electrode; a power supply unit (30) for supplying power to the electrodes; an insulating member to insulate the container, the platinum electrode and the silver electrode; and magnetic stirrer for mixing the fluid placed in the container. Plasma generated within the fluid forms platinum-silver alloy catalyst nanoparticles.    USE - The device is useful in manufacturing platinum-silver alloy catalyst (claimed) for fuel cell.    ADVANTAGE - The device simplifies the platinum-silver alloy catalyst manufacturing process by applying high energy plasma on fluid to improve the process speed and control discharge time, size, composition, dispersibility and structure of the alloy catalyst; is suitable in industrial production of the alloy catalyst; and utilizes discharged hydrogen radicals or electrons to reduce metal particles and avoids the use of chemical reducing agents to make the process environmentally friendly. The method reduces utilization of platinum by 80%, is economical, avoids poisoning problem of silver and platinum, and produces catalyst with high efficiency, which improves efficiency and durability of fuel cells.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) manufacturing platinum-silver alloy catalyst, comprising (a) mixing distilled water, electrolyte and surfactant in the container to obtain fluid solution, (b) mountin the platinum and silver electrodes on the container, (c) applying power to platinum electrode and silver electrode to generate plasma in the solution to form platinum-silver alloy catalyst; and    (2) platinum-silver alloy catalyst manufactured by the above method.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of device for manufacturing platinum-silver alloy catalyst.    Container (10)    Fluid (11)    Platinum electrode (21)    Silver electrode (22)    Power supply unit (30)