When chemical modification of the sample in electrothermal atomic absorption spectrometry (ETAAS) using a tubeor platform furnace atomizer is carried out, the smooth surface of the pyrographite substrate does not provide favorable conditions for the effective interaction of reagents and temperature resolved release of products. This goal can be reached by means of spatial separation of the reaction and evaporation from the analytical zone, narrowing of the vapor passage, supplying the reaction volume with a substrate of large surface area and using graphite as a selective adsorbent. The proposal is embodied in the design of the filter furnace atomizer. Examples of radical improvement of analytical characteristics of the ETAAS method are provided in original papers using the filter furnace to verify the necessity of alteration of basic concept for ETAAS atomization.