The present invention prevents a gas generated by evaporating a low-temperature liquid from remaining in an internal space of a booster pump and enhances efficiency of discharge and suction. A reciprocating booster pump 50 includes a cylinder 41, a piston 42, a suction check valve 65, and a discharge check valve 62. The cylinder 41 has a suction port 55 and a discharge port 56. The suction port 55 suctions a low-pressure, low-temperature liquid to an inside. The discharge port 56 boosts the low-temperature liquid and discharges the low-temperature liquid to an outside. The piston 42 reciprocates in an internal space 43 of the cylinder. The suction check valve 65 opens and closes a suction flow passage 64 between the internal space and the suction port. The discharge check valve 62 opens and closes a discharge flow passage 61 between the internal space and the discharge port. The suction check valve is configured such that if a relative pressure at the internal space establishing a pressure of the low-temperature liquid before being suctioned into the cylinder as a criterion is higher than a predetermined pressure, the suction check valve closes.