PURPOSE: To obtain an inexpensive sensible heat type heat exchanger, by a method wherein the sensible heat exchanger is provided with a pair of box type frame bodies, having fusion welding property and whose both ends are opened, and a passage, consisting of fusion welding resin sheet forming a sensible heat exchanging unit, while a plurality of blocks, in which the opening section of one end of the frame body is bonded by fusion to both ends of the passage, is laminated and bonded.

CONSTITUTION: A sensible heat type heat exchanger 1 is constituted by laminating and bonding box type frame bodies 2, having fusion welding property and whose both ends are opened, onto blocks 5, consisting of resin sheets 3 having fusion welding property with respect to the frame bodies 2. The block 5 is formed of the frame bodies 2 and the resin sheets 3, whose both side surfaces 4 are welded by fusion. According to this constitution, the block 5 can be manufactured integrally by a method wherein a pair of frame bodies 2 are arranged with a given space and the resin sheets 3, a capable of being welded to the frame bodies 2 by fusion, are arranged so as to pinch the frame bodies 2 from up-and-down directions while the superposed parts between the frame bodies 2 and the resin sheets 3 as well as both side surfaces 4 of the resin sheets 3 are welded by fusion. According to this method, manufacturing process may be shortened and the sensible heat exchanger 1, having large air stream flow passages 6 and small in the pressure loss thereof, may be manufactured.