A reference electrode according to the present invention maintains continuity between an internal solution and measurement sample and measures the electrical potential of the measurement sample even if the measurement sample in a liquid junction of the reference electrode has air bubbles mixed therein. This reference electrode is provided with: a second body provided with a second internal solution chamber in which a second internal solution is housed and a liquid junction portion disposed in the second internal solution chamber such that the second internal solution and measurement sample that is to be measured come into contact; and an internal electrode disposed inside the second internal solution. The liquid junction portion is formed from a conduction component formed from a porous or fibrous component and an aperture adjacent to the conduction component.