The method for manufacturing the water tank according to the present disclosure includes: producing an upper cylinder of a water tank; producing a lower cap of the water tank; welding the upper cylinder and the lower cap; a first polishing step of using sandpaper having a first grit range; and a second polishing step of using sandpaper having a second grit range having a larger grit than the sandpaper having the first grit range.

The method for manufacturing the water tank according to the present disclosure includes: producing an upper cylinder of a water tank; producing a lower cap of the water tank; welding the upper cylinder and the lower cap; a first polishing step of using sandpaper having a first grit range; and a second polishing step of using sandpaper having a second grit range having a larger grit than the sandpaper having the first grit range.

Provided is a liquid tank, including: a cylindrical seamless tank body having both end portions being reduced in diameter toward respective end sides; and a plurality of annular baffles provided inside the tank body and arranged at intervals in an axial direction of the tank body, in which at least one of the plurality of baffles is held on an inner peripheral surface of the tank body.

Provided is a liquid tank, including: a cylindrical seamless tank body having both end portions being reduced in diameter toward respective end sides; and a plurality of annular baffles provided inside the tank body and arranged at intervals in an axial direction of the tank body, in which at least one of the plurality of baffles is held on an inner peripheral surface of the tank body.