To provide a liquid pumping device capable of preventing condensate from accumulating on the steam-consuming device side.

A liquid tank 6 is joined, through a pipe 25, to the upstream side of the liquid inlet 4 of the liquid pumping device 1. A condensate inflow pipe 8 is joined to the upper part of the liquid tank 6. A temperature control valve 7 is joined, through a pipeline 9, to the lower part of the liquid tank 6. A working fluid supply hole 2, a working fluid discharge hole 3, and a liquid discharge hole 5 are formed in the liquid pumping device 1. A compressed air supply pipe 18 is joined to the working fluid supply hole 2. If the liquid pumping device 1 mal-functions and cannot discharge liquid through the liquid discharge hole 5, the condensate flowing into the liquid tank through the condensate inflow pipe 8 accumulates in the liquid tank 6. If the condensate is cooled to a predetermined temperature by dissipating heat, the temperature control valve 7 is automatically opened to discharge the condensate in the liquid tank 6 to the outside of the system.