To provide a method for lowering a groundwater level that can possibly reduce time and costs for work by lowering groundwater at a lower cost and in an easier manner than a conventional groundwater lowering method.

A groundwater pumping device and method pump a shallow well of a double pipe structure with an inner pipe 7 and an outer pipe 8 down to a design groundwater level with the use of a self-priming pump 3 that is connected to the inner pipe 7. The outer pipe 8 has normal slits 8-1, and the inner pipe 7 has small holes 9 up to a given wall level.