To improve durability by reducing centrifugal whirling of a rotor unit, in a liquid pump.

This liquid pump 1 uses: a stator unit 3; the rotor unit 5 integrally formed with a magnetic pole part 7 in a base end part of an impeller part 6; a housing 2 which is formed with a stator storage part SH including a partition having a bottomed cylindrical part, and storing the stator unit 3, and a rotor storage part RH storing the rotor unit 5; and a cover body 8 covering the rotor storage part RH to form a pump chamber. When a boss tube part 6c of a shaft center part of the impeller part 6 of the rotor unit 5 is made to be rotatably fitted and supported on a rotor shaft 4 whose base end part is supported in a bottom piece part 2c of the partition, the boss tube part 6c is formed such that the boss tube part 6c projects into a cylinder of the magnetic pole part 7, and the gravity center M of the rotor unit 5 is positioned on the tip side as compared to the base end of the boss tube part 6c.