To provide a method for producing a surface treatment liquid which can prevent contamination of a surface treated with the treatment liquid without loss of gloss, as well as wiping off a glass surface, a glossy metal surface or paint surface or a plastic surface, and can remain effective for a long period.

The method for producing a surface treatment liquid includes putting ethanol 60%, purified water 39.7%, and fluorine 0.7% into a rotary tank of an agitator having high-speed rotating function at that rate, and rotating the tank for more than 10 minutes at a rate of 20,000 to 25,000 revolutions.