PURPOSE: To prevent generation of stagnant flow part and to enable improvement of heat exchanging efficiency and the like by constituting so as to be provided by a means which increases flow rate of a coolant under an outlet part tube bundle, by placing an anti-vibration plate there.

CONSTITUTION: Inside an outlet part 28 of tube bundle, an anti-vibration plate 30 made of resistor element is placed and a supporting mechanism 25 of heat transfer tubes is constituted of an egg-crate type supporting mechanism 31 provided with a closure tab 32. The anti-vibration plate 30 has such a constitution of the egg-crate type supporting mechanism provided with a tab 32 as of an inner drum of the mechanism 25, for instance. In this way, since the anti-vibration plate 30 has great flow resistivity, an amount of a coolant passing through the plate 30 decreases and, to the same extent, large amount of coolant flows into underside the plate 30, and therewith flow rate distribution above and under the plate 30 is flattened.