The disinfection method of the present invention includes steps (i) and (ii). In step (i), a voltage is applied, in an aqueous liquid (21), between a counter electrode (13) and a first ion-adsorbing electrode (11) containing a first electrically conductive material (11a) capable of adsorbing an ion reversibly, thereby changing a pH of the aqueous liquid (21) to a value less than 5 or to a value greater than 9. In step (ii), the pH of the aqueous liquid 21 is adjusted to a range of 5 to 9.
