A regulating valve includes a valve body having a cylindrical portion, a valve stem inserted into the cylindrical portion and coupled to the valve body, and a locking member, in which the valve body includes a female screw including threads formed on an inner wall of the cylindrical portion and a plurality of first holes penetrating through an inner wall and an outer wall of a region of the cylindrical portion, the region having no threads of the female screw, in which the valve stem includes a male screw having threads formed on a surface close to the other end of the valve stem and at least one second hole formed in a region of the surface close to the other end of the valve stem, the region having no threads of the male screw.