A SnO2 multilayered gas sensor was prepared by using electrostatic agglomeration and electrostatic adhesion of aerosol particles, in order to develop a new system which enables simultaneous CH4 and CO sensing. The multilayer consists of an initial subsensor layer for CH4 detection and a second subsensor layer for CO detection coated on the initial layer. The initial subsensor uses a membrane prepared by electrostatic adhesion of SnO2 whisker particles. The interior SnO2 whisker subsensor layer has a lot of pores, which consist of several sizes distributed from 100 mu m to 100 nm in diameter. The second subsensor comprises a membrane prepared by electrostatic adhesion of SnO2-Pd composite particles. Electrostatic agglomeration enables composite particle preparation where Pd particles agglomerate onto a SnO2 particle. The exterior subsensor layer ensures a dendrite microstructure of the SnO2-Pd composite particles with a three-dimensional network and a uniform Pd distribution on the surface of SnO2 core particles over the whole film. The SnO2 multilayered sensor reveals a high selectivity to CH4 and CO gases, which means high sensitivity to CH4 and no response to CO of the interior subsensor, and, in turn, no response to CH4 and high sensitivity to CO of the exterior subsensor.