Abstract: In order to work up pyrotechnical material, I. the pyrotechnical material is burned in a controlled manner, the slag is optionally allowed to continue reacting and the crude gas formed is passed through a high-temperature region in which the gas is exposed to a temperature of at least 1200.degree. C. over a predetermined period in order to decompose organic substances still present; II. the crude gas formed during the combustion is cooled to a temperature below 400.degree. C.; III. the crude gas is purified under dry conditions by first feeding it into a preliminary separator, coarse particles being separated off, and then feeding the crude gas via fine dust filters in order to separate off finely divided solids and/or IV. the crude gas is optionally purified under wet conditions by first passing it through a rotary scrubber and then passing it via one or more absorption units and V. the purified gas is released as waste air.