A metal heat treatment furnace comprising: an internal heating chamber configured to heat metal to be heat-treated and provided in a vacuum vessel with an induction heating portion; a cooling chamber provided below the heating chamber and configured to cool the metal to be heat-treated, which has been heated by the heating portion; a hollow connection section having a heat insulating function configured to connect the heating chamber and the cooling chamber and provided with a movable gate which partitions the heating chamber and the cooling chamber; a first movable heat-shield panel arranged in a lower portion in the heating chamber and configured to shield heat from the heating chamber; a second movable heat-shield panel arranged in an upper portion in the cooling chamber and configured to shield heat of the heated metal to be heat-treated from being transferred to the gate; characterised by a water-cooled vertically movable shaft disposed through the bottom portion of the cooling chamber, configured to be capable of supporting the metal to be heat-treated and entering the heating chamber, and in that the heating portion includes a coil supported so that pitches thereof can be adjusted as desired according to sizes or shapes of alloy to be heated and a heating element using carbon which generates heat when an electric current is fed to the coil, the pitches of the induction coil being adjustable by a vertical movement of the induction coil secured to a shaft portion of a movable knob slidable in the vertical direction in a state of being fitted into a slit of a narrow plate-shaped coil supporting member, the movement of the induction coil being caused by an operation of the movable knob, wherein, when pitches of the induction coil are adjusted so as to make the temperature distribution in the interior of the heating portion uniform, in a state in which the alloy to be heated is loaded in the heating chamber, uniform heating property is ensured in the range of ±5°C. an internal heating chamber configured to heat metal to be heat-treated and provided in a vacuum vessel with an induction heating portion; a cooling chamber provided below the heating chamber and configured to cool the metal to be heat-treated, which has been heated by the heating portion; a hollow connection section having a heat insulating function configured to connect the heating chamber and the cooling chamber and provided with a movable gate which partitions the heating chamber and the cooling chamber; a first movable heat-shield panel arranged in a lower portion in the heating chamber and configured to shield heat from the heating chamber; a second movable heat-shield panel arranged in an upper portion in the cooling chamber and configured to shield heat of the heated metal to be heat-treated from being transferred to the gate; characterised by a water-cooled vertically movable shaft disposed through the bottom portion of the cooling chamber, configured to be capable of supporting the metal to be heat-treated and entering the heating chamber, and in that the heating portion includes a coil supported so that pitches thereof can be adjusted as desired according to sizes or shapes of alloy to be heated and a heating element using carbon which generates heat when an electric current is fed to the coil, the pitches of the induction coil being adjustable by a vertical movement of the induction coil secured to a shaft portion of a movable knob slidable in the vertical direction in a state of being fitted into a slit of a narrow plate-shaped coil supporting member, the movement of the induction coil being caused by an operation of the movable knob, wherein, when pitches of the induction coil are adjusted so as to make the temperature distribution in the interior of the heating portion uniform, in a state in which the alloy to be heated is loaded in the heating chamber, uniform heating property is ensured in the range of ±5°C.