Abstract: A check vale for injecting gas comprises: an integrally formed body provided with a corrugated portion having a diameter smaller than other areas on an outer surface of an upper portion of a gas flow hole; an integrally formed spindle perpendicularly penetrating the body and provided with a corrugated portion having a diameter smaller than other areas on an outer surface of a lower portion of the gas flow hole of the body; a spring penetrating an upper end portion of the spindle; a spring seat for fixing the spring penetrating the upper end portion of the spindle and for guiding the spindle to a perpendicular position; a coupling ring coupled to an upper end of the body for fixing the body to a prechamber; and a spacer coupled to a lower end of the body for fixing the lower end of the body that covers an outer edge of the spindle to the prechamber.