To provide a pump for liquid, for preventing gas from being stored in a pump.

A pump 10 is a centrifugal pump, in which an impeller 46 is disposed in a casing 14, delivered liquid is sucked from a suction port 28 and pressure of the delivered liquid is increased by rotating the impeller 46 by a shaft 40, and the delivered liquid is discharged from a discharge port 30. A gas-bleeding hole 62 is formed in a back face part of an expeller 54 of an expeller ring 22, and a capillary tube 64 is connects with the bleeding hole 62. When gas such as air is piled up on a back side of the expeller 54, the gas is discharged through the bleeding hole 62 and capillary tube 64.