Today biomass burning is accepted to be an important source of many trace gases affecting atmospheric chemistry (Crutzen et al., 1979; Cofer et al., 1988a; Radke et al., 1988; Crutzen et al., 1990). Despite its global significance and in contrast to fossil fuel use, where detailed investigations on global amounts and their distributions are available, still little quantitative information is know about the emissions of some of the compounds emitted and the global amounts consumed by biomass burning. Estimates of these global quantities are difficult to derive because of a very uncertain data base. The most recent values published by Crutzen et al. (1990) indicate that 1900 to 5000 teragrams (Tg) biomass carbon is released annually. In order to obtain more reliable emission data, improvement of measurement techniques as well as methods for calculating emission data are required. A growing number of measurements on biomass burning emissions have been published since the first estimates (Crutzen et al., 1979), but some of the trace gas emissions are still very uncertain or even unknown as, for example, in the case of some nitrogen-containing species. Most of the data on biomass burning emissions were derived from airborne measurements above large-scale fires. An experimental system, on the other hand, is advantageous in cases when information cannot be derived from open fires or when field measurements are inappropriate. In this chapter we describe results obtained by the latter technique. An important advantage of the apparatus described is the possibility of learning about burning behavior and burning stages, and thus clarifying relationships between combustion processes and emissions, finally leading to new methods for estimating emissions.