To obtain a safe detergent that reduces the doubt and anxiety about the safety of substances that enhance the detergency of conventional surfactants, organic compounds, and the like, and can minimize allergic reactions and the biological concentration of hazardous substances due to the long-term use, and is friendly to environments and human bodies and decrease the amount of the surfactants, and the like, remaining on products, and the like.

An acidic aqueous solution and an alkaline aqueous solution containing silicic acid are mixed to make the objective product viscous or convert it to a gel form.