Abstract: A process for drying wood at subatmospheric pressures comprising a phase in which the wood is heated up in a sealed environment, is characterized in the fact that this heating-up phase comprises the operations of:I. introducing into said closed environment an operative fluid which is capable of imparting, moisture to the wood, causing this fluid to cycle repeatedly around a closed circuit in such a way that in every cycle, the fluid passes through a pile formed by the pieces of wood, and then returns without passing through the pile;Ii. supplying thermal energy to the operative fluid in such a way that the thermal content of the fluid increases overall in each cycle at a diminishing rate until the fluid reaches a substantially steady cyclical state in which there is no overall increase in its thermal content in each subsequent cycle.