A stack type evaporator comprises tubular elements (1) each having a plurality of inwardly protruding recessed ribs (7) which extend from an upper header portion (1a) of the element to a lower header portion (1b), with the ribs serving as straight drain canals (7a). A hydrophilic resin coating of a specific composition covers the outer surfaces of the tubular elements (1) and fins (2) each interposed between two adjacent tubular elements. The combination of straight drain canals with the specific hydrophilic resin coating is effective to facilitate the drainage of condensed water so that the waterdrops are perfectly prevented from flying out of the evaporator and that any stinking mold or mildew is not permitted to grow within a reduced amount of remaining adherent water. Also, the hydrophilic coating itself does not emit any unpleasant smell.