A liquid measuring device includes a floating member that is moved in accordance with a liquid surface, a first magnetic field generator that is disposed in the floating member and positions its north (N) pole to face a first direction, a second magnetic field generator that is disposed in the floating member to be spaced apart from the first magnetic field generator and positions its south (S) pole to face the first direction, and a plurality of proportional output-type hole elements that detect magnetic fields generated by the first magnetic field generator and the second magnetic field generator in positions facing the first direction.