To reduce manufacturing cost of a two-stage type heating furnace.

A two-stage type heating furnace 10 includes a lower part heater 2 disposed on a base 1, a first workpiece supporter 3 disposed on the lower part heater 2, a second workpiece supporter 4 disposed on the first workpiece supporter 3, and an upper part heater 6 disposed on the second workpiece supporter 4 and attached to an upper wall 5. The second workpiece supporter 4 includes a pair of workpiece support pipes 4a, 4a arranged to extend straight in the horizontal direction (X direction) and held telescopically in the X direction, and a plurality of second workpiece support bars 4b extended between the workpiece support pipes 4a, 4a with a predetermined distance provided therebetween. The workpiece support pipes 4a, 4b have a hollow structure in which cooling water is injected from an injection hole 8 at one end and discharged from a discharge hole 9 at the other end.