To eliminate warming in a half-finished manner before heating a material to be heated in a heating space, by providing a heating furnace for heating the material conveyed from an inlet while moving the material, and a means for conveying the material to the space at faster speed than a moving speed of the material in the space.

A heating furnace 1 has a heating space 1a for heating a material to be heated conveyed from an inlet while moving the material and delivering the material from an outlet. More specifically, an internal heater 1b and a fan 1c are provided in the space 1a which is heated by the heater 1b, and agitated by the fan 1c. A conveyor 2 drives a pallet 10 containing the material in a placing state, moves the pallet 10 toward an outlet in the space 1a of the furnace 1, and delivers the pallet 10 from an outlet. A forcing pusher (rapid conveying means) 7 forces the pallet 10 at a faster speed than that of the conveyor 2 to convey the material to the space 1a.