To provide a groundwater draining method which exerts high efficiency in collecting and draining groundwater in a landslide slope, and to provide a catchment well.

The groundwater draining method is provided for draining groundwater under the landslide slope A. To implement the method, collecting pipes 5 each having a strainer are embedded in the ground so as to interrupt water channels under the landslide slope A. Then an upper edge 5a of the collecting pipe is located near the ground surface of the slope, and a lower edge of the same is connected to a vertical well 2, to thereby collect the groundwater which the collecting pipe 5 has caught via the strainer to the vertical well 2 and drain the groundwater from the vertical well 2 to the outside of the slope.