Multiple cooling-storage containers are arranged in respective spaces formed between neighboring refrigerant tubes. The cooling-storage container is made of a pair of outer envelope portions, each forming a side wall. Multiple convex portions and concave portions are formed in the side walls so that air passages are formed between refrigerant tubes and the concave portions. A sectional area of the air passage formed in a lower portion of the cooling-storage container below a predetermined height is made larger than that of the air passage formed in an upper portion of the cooling-storage container above the predetermined height.