NOVELTY - Gold grains of diameter below 5 nm are added to an organic solution, and oxygen is then added to the organic solution to form auric oxide solution. A porous metal carrier (2) of diameter greater than 5 nm is added to the auric oxide solution for enabling auric oxide (1) to be adhered to the pores (21) of porous metal carrier, to produce a nanometered gold catalyzer (3) with porous metal carrier.    USE - For producing nanometered gold catalyzer used in mouth-muffle, fire prevention mask unit, water heater, carbon monoxide alarm, for treating exhaust from semiconductor, fuel battery for converting carbon monoxide into carbon dioxide, and converting ozone into oxygen.    ADVANTAGE - The method provides nanometered gold catalyzer which is compact, lightweight and usable in variety of products for eliminating carbon dioxide poisoning accidents and reducing air pollution due to exhaust gas from motor vehicles. The activeness of catalyst can be maintained for more than 200 hours. The mouth-muffle coated with catalyzer helps people escape from fire or fireman rescue people from fire. The catalyzer reduces the concentration of carbon monoxide from 2500 ppm at the inlet to 5 ppm at the outlet of muffle. The nanometered gold catalyzer when used in battery prevents damaging of electrode due to carbon monoxide and improves battery performance. The catalyzer improves air quality by converting high concentration ozone in air to oxygen. The catalyzer when used in wire gauze filter converts high concentration hydrogen into water which is not harmful to environment. The catalyzer is effective such that 1 g of the catalyzer oxidizes 5 liters of carbon monoxide of concentration 10000 ppm within 1 minute.    DETAILED DESCRIPTION - The metal carriers are obtained from lead zinc, aluminum, iron, copper, titanium or cobalt.    DESCRIPTION OF DRAWING(S) - The figure shows the schematic drawing of the synthesis of nanometered gold catalyzer.    auric oxide grains (1)    metal carrier (2)    gold catalyzer (3)    pores (21)