A method of measuring pH of an analyte solution comprising: a step for sensing the liquid temperature of the analyte solution, a step for calculating a compensated pH value in the reference electrode internal liquid comprising: using electrodes, in which a pair of the electrodes consists of a glass electrode which encloses a glass electrode internal liquid including saturated potassium chloride and a glass electrode buffer solution inside, and a reference electrode which encloses a reference electrode internal liquid including saturated potassium chloride and a reference electrode buffer solution inside, calculating a corrected pH value of the reference electrode buffer solution from an inherent pH value of the reference electrode buffer solution according to the liquid temperature, calculating a value of a potential variation of the reference electrode internal liquid according to the concentration of the potassium chloride thereof, calculating a deducted pH value of the reference electrode internal liquid from the value of the potential variation according to the liquid temperature, and then, calculating a compensated pH value of the reference electrode internal liquid by subtracting the deducted pH value of the reference electrode internal liquid from the corrected pH value of the reference electrode buffer solution, a step for sensing a voltage generated between the electrodes in the analyte solution, and a step for detecting a pH value of the analyte solution comprising: calculating a pH difference from the voltage according to the liquid temperature, and then detecting the pH value of the analyte solution from the pH difference according to the compensated pH value of the reference electrode internal liquid. a step for sensing the liquid temperature of the analyte solution, a step for calculating a compensated pH value in the reference electrode internal liquid comprising: using electrodes, in which a pair of the electrodes consists of a glass electrode which encloses a glass electrode internal liquid including saturated potassium chloride and a glass electrode buffer solution inside, and a reference electrode which encloses a reference electrode internal liquid including saturated potassium chloride and a reference electrode buffer solution inside, calculating a corrected pH value of the reference electrode buffer solution from an inherent pH value of the reference electrode buffer solution according to the liquid temperature, calculating a value of a potential variation of the reference electrode internal liquid according to the concentration of the potassium chloride thereof, calculating a deducted pH value of the reference electrode internal liquid from the value of the potential variation according to the liquid temperature, and then, calculating a compensated pH value of the reference electrode internal liquid by subtracting the deducted pH value of the reference electrode internal liquid from the corrected pH value of the reference electrode buffer solution, using electrodes, in which a pair of the electrodes consists of a glass electrode which encloses a glass electrode internal liquid including saturated potassium chloride and a glass electrode buffer solution inside, and a reference electrode which encloses a reference electrode internal liquid including saturated potassium chloride and a reference electrode buffer solution inside, calculating a corrected pH value of the reference electrode buffer solution from an inherent pH value of the reference electrode buffer solution according to the liquid temperature, calculating a value of a potential variation of the reference electrode internal liquid according to the concentration of the potassium chloride thereof, calculating a deducted pH value of the reference electrode internal liquid from the value of the potential variation according to the liquid temperature, and then, calculating a compensated pH value of the reference electrode internal liquid by subtracting the deducted pH value of the reference electrode internal liquid from the corrected pH value of the reference electrode buffer solution, calculating a corrected pH value of the reference electrode buffer solution from an inherent pH value of the reference electrode buffer solution according to the liquid temperature, calculating a value of a potential variation of the reference electrode internal liquid according to the concentration of the potassium chloride thereof, calculating a deducted pH value of the reference electrode internal liquid from the value of the potential variation according to the liquid temperature, and then, calculating a compensated pH value of the reference electrode internal liquid by subtracting the deducted pH value of the reference electrode internal liquid from the corrected pH value of the reference electrode buffer solution, a step for sensing a voltage generated between the electrodes in the analyte solution, and a step for detecting a pH value of the analyte solution comprising: calculating a pH difference from the voltage according to the liquid temperature, and then detecting the pH value of the analyte solution from the pH difference according to the compensated pH value of the reference electrode internal liquid. calculating a pH difference from the voltage according to the liquid temperature, and then detecting the pH value of the analyte solution from the pH difference according to the compensated pH value of the reference electrode internal liquid.