To provide a pipe for underground heat exchange with favorable heat exchange efficiency, capable of reducing a facility cost and an operation cost.

A heat medium pipe part 1 is provided wherein a heat medium flows and makes a U-turn, and the heat medium pipe part 1 is composed by connecting a plurality of upstream side heat transfer pipes 2 to one downstream side return pipe 3. A hole sectional area of the one return pipe 3 is set smaller than a total sum of hole cross sectional areas of the plurality of heat transfer pipes 2. An uneven part 4 comprised by plurally forming protrusion like parts or groove like parts continuous in a pipe part axial direction at a predetermined pitch in a pipe part circumferential direction is provided on one or both of an outer circumference and an inner circumference of the heat transfer pipe 2.