The present invention provides one kind and can keep bactericidal effect for a long time and inhibit the liquid oral detergent using electrolysis water of metal protection. The liquid oral detergent that aforesaid liquid cleaning agent for mouth cavity is the electrolysis water being positive containing oxidation-reduction potential, menthol, anionic surfactant and water-miscible organic solvent and pH is 6~8. Preferably, any a kind or more in aforementioned menthol or aforementioned anionic surfactant is stored in a manner of mutually non-touching with aforementioned electrolysis water, and is used when in use with admixture.本發明提供一種能够長期保持殺菌效果、並且抑制了金屬腐蝕性的使用電解水的液體口腔清潔劑。上述液體口腔清潔劑是含有氧化還原電位爲正的電解水、薄荷醇類、陰離子性表面活性劑和水溶性有機溶劑、並且pH爲6～8的液體口腔清潔劑。優選地，將前述薄荷醇類或前述陰離子性表面活性劑中的任意1種以上與前述電解水以相互不接觸的方式收納，並在使用時以混合狀態使用。
