According to the present invention, an aqueous hydrogen peroxide solution can be provided, which can be used for decreasing the number of bacteria and is characterized by containing hydrogen peroxide, a phosphate salt and an aluminum salt as essential components. According to the present invention, a disinfection method can also be provided, which is characterized by mixing air with a mist of the aqueous hydrogen peroxide solution and/or a gas of the aqueous hydrogen peroxide solution and then bringing the resultant mixture into contact with a material to be disinfected.藉由本發明可提供一種用以使菌數減少的過氧化氫水溶液，其特徵為含有過氧化氫、磷酸鹽及鋁鹽作為必要成分。藉由本發明，更可提供一種殺菌方法，其特徵為將空氣和此過氧化氫水溶液之霧氣及/或氣體混合後，使其接觸對象物。
