An apparatus is described in which solid samples of reactive materials are quenched following heating in a small drop‐away vacuum furnace chamber. The principal feature is that the furnace is supported by the differential pressure between the furnace chamber and its surroundings. Thus, when the quenching gas is injected over the sample in the furnace chamber the vacuum is instantly broken, causing the furnace to drop away from the sample. By using chilled helium gas, quenching rates up to 1.8×104°C/sec have been achieved with 0.25 mm thick samples. Higher cooling rates should be attainable by the use of thinner samples and higher gas velocities and possibly by improving the quench nozzle design. The simplicity of the unit and the small volume to be evacuated are attractive features.