To obtain a hair setting agent in which setting force of hair is enhanced while lowering a formulation ratio of prescribed ingredients.

In the hair setting agent for setting the hair in which prescribed ingredients are mixed, an alkaline water having a surface active effect is mixed therein. Permeation and reduction actions of a first agent for permanent wave which is the hair setting agent can be enhanced by surface active effect of the alkaline water even when the formulation ratio of ingredients such as thioglycolic acid and monoethanolamine is lowered. Consequently, effective perming treatment can be carried out by enhancing reduction action, and the like, while lowering the formulation ratio of ingredients such as thioglycolic acid and monoethanolamine and suppressing damage on the hair.