A liquid analyzer may include a reference electrode provided with internal liquid containing a halide ion; and an ion electrode of which a measurable concentration range for a measuring target ion is lower than the concentration of the halide ion in the internal liquid of the reference electrode, The internal liquid of the ion electrode contains the measuring target ion and a halide ion; and the internal liquid of the ion electrode is liquid in which the concentration of the measuring target ion and the halide ion are regulated such that an osmotic pressure and an isothermal point of the internal liquid of the ion electrode respectively have desired values, and the isothermal point is included in the measurable concentration range, and the concentration of the halide ion is different from the concentration of the halide ion in the internal liquid S33 of the reference electrode.