To prevent the generation of noises when a primary valve of a regulator is less opened and there is a greater pressure difference between a pressure resistant container and a primary chamber.

A primary valve element 13 is mounted with a damping member 39 held therein, without being mounted directly on a primary valve lever 15. Even when a small gap between a seat surface 12A of a primary valve seat 12 and an abutment surface 13A of the primary valve element 13 generates a turbulence with LPG flowing at a high velocity and causes the vibration and resonance of the primary valve element 12, the damping member 39 works for absorption and moderation to prevent the vibration of the primary valve lever 15 and prevent noises which are generated by the vibration of the primary valve lever 15.