To prevent warp and crystal lattice defects in a wafer from being developed by lessening a temperature gradient while transferring the wafer into or out from a furnace tube of a hot wall batch-type heat treatment system.

An auxiliary liner tube 9 which is preheated in a furnace tube 1, is taken out to the waiting chamber 5 side, and here a boat 6 into which are loaded with a wafer W, is put in the auxiliary liner tube 9 temporarily, and then it is transferred into the furnace tube 1. Exhaust gas in a closed space S formed at this moment, is exhausted not through the side wall of the bottom of the furnace center tube 1, but through the second exhaust tube 16 which is connected with the flange of an insulating cylinder 7, a lower part of the boat 6, by changing a valve V3. The boat is transferred out in the reverse order. While the wafer W is put in the auxiliary liner tube 9, it is heated by the radiant heat from the wall and the flowing-in atmosphere gas which is heated by the exhaust, therefore the temperature, while the wafer is transferred into/from the furnace tube 1, rises higher than in conventional systems and lessens the temperature gradient.