PURPOSE: To reduce a mounting space by a method wherein an end part of a tube is closed by a plate, and a distribution chamber and a collecting chamber communicating with a cooling fluid flow passage are formed by defining an inner wall surface of the plate, an inner peripheral wall surface at the end part of the tube and an end surface of the wall.

CONSTITUTION: A going flow passage 13a and a returning flow passage 13b for use in flowing refrigerant through a tube main body 10 are formed in the tube main body 10. The flow passage 13a and the flow passage 13b are separated from each other by a partition wall 13c for their adjoining flow passages 13a or the adjoining flow passages 13b. Between a plurality of flow passages 13a and a plurality of flow passages 13b is formed a dividing wall 13d extending from one end of the tube main body 10 at a side forming a distribution chamber 12a and a collecting chamber 12c toward the other end. Then, the distribution chamber 12a and the collecting chamber 12c are formed within one end of the tube main body 10 and in turn a bending-back chamber 12b is formed within the other end. A function of a tank part constituted by separate component parts in the prior art can be incorporated in the tube main body 10.