top and bottom dies used in the first embodiment of present invention and a heating heating chamber capable of continuously moving the plural pairs of the top and bottom dies the preparatory process in this embodiment is the same as that in the above described first embodiment and therefore its details will not be described here and the details of the heating compressing and cooling processes in this embodiment will be described below a multilayered fibrous material block 50 is placed on each of the bottom dies 32 in the first embodiment at this stage the position of the top die 22 is such that a gap is present between the top die 22 and the ventilatory sheet 5 on the top side the interior of the heating chamber has been preheated to a desired temperature by a heater 12 in this state the bottom die 21 on which the multilayered fibrous material block 50 is resting and the top die 22 set on the multilayered fibrous material block 50 are moved into the heating chamber the heating chamber contains a moving means for moving the top and bottom dies 22 and 21 in the heating chamber the distance between the bottom and top dies 21 and 22 is maintained at a desired distance by this die moving means the distance between the bottom and top dies can be optionally set as described before the plural pairs of top and bottom dies are prepared and are sequentially moved through the heating chamber the size length of the heating chamber is determined in accordance with the.