Sterilization method, formulation for sterilization use, and device for producing sterilizing liquid

A sterilization method comprising:

• synthesizing peroxynitric acid (HOONO2) by chemical reaction under acidic conditions of a pH value of 2 or lower to preserve a liquid containing the peroxynitric acid (HOONO2);
• and
• diluting the preserved liquid containing the peroxynitric acid (HOONO2) with a buffer solution, and applying the resultant liquid to an object to be sterilized under acidic conditions of a pH value of 4.8 or lower, thereby to increase the concentration of hydroperoxy radicals (HOO.) produced in the preserved liquid containing the peroxynitric acid (HOONO2);
• and
• sterilizing the object to be sterilized by microbicidal activity of the hydroperoxy radicals (HOO.).