The surface morphology of the deposits, studied by scanning lepton (SEM) and atomic force (AFM) microscopes, has uniform distributions of grains within the films and grains area unit within the Nanocrystalline dimensions AFM analysis evidenced the presence of spherical silver particles on the catalyst surface and provided quantitative surface parameters as form dimension, surface roughness and mean particle diameter. In this work a new approach was manufactured sensors for poison gases (CO, H2) that effects on the quality of life. The sensitivity toward (CO, H2) poison gases has been measured under 10 ppm concentrations. SnO2 doped with 15 % Ag noble metal has a big sensitivity and increase in the sensing current for poison gases (CO, H2). The thermal annealing effect of the sensitivity thin films SnO2 doped with 15 % Ag to the poison gases has been studied

Fabrication Sensors, Toxic Gases, SnO2.