Abstract: Procedure for drying an organic material, most suitably one which is xylogenic (originating from wood), such as veneers for instance, by means of hot circulating air which circulates in the drying space from a blower to a heat exchanger, passes by the organic material, collecting the water vapor released by the material, and further to the blower, whereafter part of the air/water vapor mixture is conducted through a vent, throttled by means of a damper, into the free atmosphere. In the drying space, the temperature and pressure are monitored, and the damper is used to control the vented air quantity in such manner that there is continuously a given, predetermined vacuum in the drying space.