PURPOSE: To obtain a heat exchanger in which dew condensation water generated on an inner surface of an upper wall is guided to an innermost part of the wall and the water is not dropped on a storage article.

CONSTITUTION: A heat exchanger is provided in a cooling chamber, and has an aluminum panel 1 having a refrigerant passage 3 and bent substantially in a U shape. Front edges 13a, 15a of both sidewalls 13, 15 are obliquely cut out, an innermost part of an upper wall 11 becomes low, and hence the exchanger is mounted in the chamber. A refrigerant passage 3b protruding from an inner surface of the wall 11 is formed in a curved state, and formed in a shape that dew condensation water flowing along an oblique inner surface of the wall 11 is guided to the innermost part of the wall 11.