To provide a continuous gas quenching method and its system with which the gas quenching to a metal can be performed in a little strain and good efficiency without requiring much of resources.

In this continuous gas quenching method and its system, one or a plurality of heating furnaces which can heat to a last quenching temperature, and one of a gas quenching exclusive apparatus, are connected in direct or indirect state or in series or parallel state. Then, works heated to the quenching temperature in the last heating furnace or each heating furnace, are shifted to the gas quenching exclusive apparatus from this heating furnace through vacuum or inert gas atmosphere, and the gas quenching is applied in order at a transformation temperature containing an isothermal holding with the above gas quenching exclusive apparatus.