Despite a variety of catalysts for low-temperature carbon monoxide oxidation, only hopcalite type catalysts and Pd/Al2O3 are mainly used in respiratory protection devices (gas masks and small-size apparatuses for air purification). However, these catalysts have a number of drawbacks. The poisoning of hopcalite with aqueous vapor and high contents (up to 5 mass %) of palladium in Pd/Al2O3 are the most considerable among them. We have shown that metal-complex compounds of Pd(II) and Cu(II) anchored to different carriers have the best properties of both homogeneous and heterogeneous catalysts for low-temperature carbon monoxide oxidation. Their activity can be changed by varying a ratio of components supported, by changing a ligand nature, and by alteration of a type of bonding between a central atom and a functional group of a carrier. The high activity and stability was demonstrated by tripoli-supported halogenide complexes of Pd(II) and Cu(II). As was found, at low CO concentrations (from 100 mg/m3 to 300 mg/m3), the steady-state regime was attained soon and the reaction order was 1 with respect to CO while dependences of the reaction rate in the steady-state regime (Wst) on Pd(II) : Cu(II) : X- ratio (X- = Cl- and Br-) were complicated. The synergism in catalytic activity of Pd(II) and Cu(II) at their ratio 1 : 1 was observed and final CO concentrations were much lower than the maximum permissible one (MPC = 20 mg/m3) for a long time. Very complicated Wst dependences on the content of halogenide ions are evidence of the formation of surface complexes of different compositions. The activity of the catalyst proposed was found to grow with the increase in the water content (up to 0.1 g/g), so, a role of the carrier did not come only to its influence on thermodynamic properties of the surface complexes but also on the behavior of the water adsorbed. The longterm testing to determine protective properties of the catalyst has shown both its advantages in comparison with the well-known ones and its usefulness for equipment of gas masks against carbon monoxide.