To prevent a water suction effect from being impaired even if the underground water level falls regarding an underground water suction device and an underground water suction method.

A strainer pipe 2 having inflow holes 2a of underground water is laid to reach below the underground water level WL from the ground surface G by free jacking allowing bending excavation. A water suction pipe 3 having water absorbing holes 3b located below the underground water level WL within the strainer pipe 2, in a specific part 3a in a longitudinal direction, is inserted in the strainer pipe 2. Since the water suction holes 3b are thus provided limited to the specific part 3a of the water suction pipe 3, even if a part of the water suction pipe 3 is exposed to air due to the fall of the underground water level WL, efficient water absorption can be continuously performed while the specific part 3a provided with the water suction holes 3b is kept unexposed to air.